1
|
Santhanam V, Modi P, Mishra UK, Jahan I, Ramesh NG, Deep S. Rational design and synthesis of novel triazole- and tetrazole-fused iminosugars as potential inhibitors of amyotrophic lateral sclerosis (ALS) linked SOD1 aggregation. Int J Biol Macromol 2023; 253:126900. [PMID: 37714236 DOI: 10.1016/j.ijbiomac.2023.126900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 08/25/2023] [Accepted: 09/12/2023] [Indexed: 09/17/2023]
Abstract
In this manuscript we report the first example of an iminosugar that inhibits superoxide dismutase fibrillation associated with the amyotrophic lateral sclerosis (ALS). The present work involves synthesis of novel triazole and tetrazole embedded iminosugars, synthesized in 11-13 high yielding steps starting from readily available tri-O-benzyl-D-glucal and proceeding through a concomitant azidation - thermal intramolecular [3 + 2] cycloaddition reaction as the key step. One of these pre-designed iminosugars was found to inhibit fibrillation of SOD1 and also has shown propensity to break pre-formed fibrils. Docking and MD simulation studies suggest that the most probable interaction of this compound is a hydrogen bonding with Arg69, a loop IV residue of SOD1, which has a crucial role in stabilizing the native conformation of SOD1.
Collapse
Affiliation(s)
- Venkatesan Santhanam
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| | - Priya Modi
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| | - Umesh K Mishra
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| | - Ishrat Jahan
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| | - Namakkal G Ramesh
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India.
| | - Shashank Deep
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India.
| |
Collapse
|
2
|
Mishra UK, Sanghvi YS, Abhiraj R, Sampathkumar SG, Ramesh NG. An expeditious synthesis of novel DNA nucleobase mimics of (+)-anisomycin. Carbohydr Res 2022; 520:108645. [PMID: 35964481 DOI: 10.1016/j.carres.2022.108645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 08/01/2022] [Accepted: 08/01/2022] [Indexed: 11/15/2022]
Abstract
A glycal based expeditious synthesis of novel nucleoside analogues of (+)-anisomycin is reported. Readily available tri-O-benzyl-D-glucal was converted to a partially protected trihydroxypyrrolidine that is used as a common scaffold for the introduction of various nucleobases at the primary hydroxyl centre. Nucleoside analogues possessing all four DNA bases have been synthesized. Selective acetylation at C3 position was carried out with two of these unnatural nucleosides in order to mimic the structure of (+)-anisomycin. Cytotoxicity studies of some of these nucleosides showed that they display weaker activity on HeLa cells than Ara-C.
Collapse
Affiliation(s)
- Umesh K Mishra
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, 110016, India
| | - Yogesh S Sanghvi
- Rasayan Inc., 2802 Crystal Ridge Road, Encinitas, CA, 92024-6615, USA
| | - R Abhiraj
- Laboratory of Chemical Biology, National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | | | - Namakkal G Ramesh
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, 110016, India.
| |
Collapse
|
3
|
Murphy PV, Ramesh NG. Carbohydrate Chemistry: Critical for our Future. CHEM REC 2021; 21:2928-2929. [PMID: 34766718 DOI: 10.1002/tcr.202100283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Paul V Murphy
- SSPC - Science Foundation Ireland Research Centre for Pharmaceuticals, CÚRAM - Science Foundation Ireland Research Centre for Medical Devices, School of Biological and Chemical Sciences, National University of Ireland Galway, University Road, Galway, Ireland, H91 TK33
| | - Namakkal G Ramesh
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, 110016, India
| |
Collapse
|
4
|
Ramesh NG. From Glycals to Nitrogen Heterocycles and Carbocycles via "Cleavage-Intramolecular Recombination Strategy". CHEM REC 2021; 21:2930-2957. [PMID: 34472196 DOI: 10.1002/tcr.202100187] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 08/06/2021] [Accepted: 08/11/2021] [Indexed: 12/17/2022]
Abstract
Glycals (carbohydrate enol-ethers) have enjoyed profound applications in organic synthesis for more than a century. They not only serve as versatile glycosyl donors or as substrates for Ferrier rearrangement, but also find extensive synthetic applications especially as a "chiral pool" for accomplishing the synthesis of a variety of natural and biologically important compounds. As cyclic enol ethers, they demonstrate high reactivity and are among the most and variously transformable monosaccharide derivatives. The uniqueness of the reactivity of glycals is that they can be synthetically tuned to get a library of derivatives through stereo- and regioselective introduction of a variety of functional groups at C1, C2, C3 as well as C4 carbons of the sugar. We have developed a practical approach for stereoselective mono- and diamination of glycals and over the years utilized these scaffolds for the synthesis of a variety of biologically important nitrogen heterocycles and carbocycles through a "Diversity Oriented Approach". Our synthetic strategy in this direction mainly relied on the cleavage of ring O-C bond of the sugar followed by an "intramolecular recombination" reaction. Utilizing this strategy, we have accomplished the synthesis of several biologically important natural products, their analogues and related unnatural derivatives. Examples of such compounds reported from our group include polyhydroxypyrrolidines, DMDP, anisomycin, steviamine, pochonicine, conduramines, bulgecinine, aminocyclitols, azepanes, 4-hydroxy-D-proline, azanucleosides and their analogues. A personal account highlighting these syntheses is presented here.
Collapse
Affiliation(s)
- Namakkal G Ramesh
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, 110016, India
| |
Collapse
|
5
|
Abstract
Design of Janus-faced or double-headed homoazanucleosides with the possibility to undergo self-organization through base pairing has been conceptualized and accomplished. The synthetic strategy demonstrates the unique ability to introduce two similar or complementary nucleobases on opposite arms of a chiral polyhydroxypyrrolidine while also ensuring that their faces are anti to each other to allow only intermolecular interactions between the nucleobases, an essential requisite for self-assembly. Single-crystal X-ray structures were determined for all three types of homoazanucleosides, one possessing two adenine molecules, the other with two thymine moieties, and the third containing both adenine and thymine. The crystal structures of all three display noncovalent interactions, including Watson-Crick base pairing, Hoogsteen H-bonding, and π-π stacking, resulting in unusual supramolecular patterns. The most striking supramolecular motif among them, which emerged from the crystal structure of the homoazanucleoside containing both adenine and thymine, is a left-handed helix formed through Watson-Crick pairing between nucleobases. The present study thus forms a prelude to the design of Janus-faced building blocks to establish helical pillars as well as lateral branches that together define a three-dimensional (3D) lattice. The ready accessibility of these molecules is expected to spur the next generation of discoveries in the design of functional nanomaterials.
Collapse
Affiliation(s)
- Umesh K Mishra
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| | - Yogesh S Sanghvi
- Rasayan Inc., 2802 Crystal Ridge Road, Encinitas, California 92024-6615, United States
| | - Martin Egli
- Department of Biochemistry, School of Medicine, Vanderbilt University, Nashville, Tennessee 37232, United States
| | - Namakkal G Ramesh
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| |
Collapse
|
6
|
Abstract
Synthesis of novel homoazanucleosides and their peptidyl analogs as hybrid molecules comprised of amino acids, an iminosugar and natural nucleobases is reported for the first time. A pluripotent amino-substituted chiral polyhydroxypyrrolidine, possessing orthogonally different functional groups on either arm of the pyrrolidine ring, served as an ideal substrate for the synthesis of the proposed peptidyl homoazanucleosides. The acid sensitive primary benzyloxy group, on one arm of the pyrrolidine ring, after selective deprotection, was utilized for the introduction of nucleobases to obtain the homoazanucleosides. The amino group on the other side offered the opportunity to be coupled with amino acids to deliver the desired peptidyl homoazanucleosides. Glycosidase inhibition studies revealed that the acetamido derivatives of homoazanucleosides were found to be sub-millimolar inhibitors of β-N-acetyl-glucosaminidase.
Collapse
Affiliation(s)
- Rahul Vilas Salunke
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi - 110016, India.
| | - Pawan Kumar Mishra
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi - 110016, India.
| | - Yogesh S Sanghvi
- Rasayan Inc., 2802 Crystal Ridge Road, Encinitas, CA 92024-6615, USA
| | - Namakkal G Ramesh
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi - 110016, India.
| |
Collapse
|
7
|
Kumar Mishra U, Ramesh NG. A carbohydrate based straightforward approach to trans-4-hydroxy-d-proline and trans-4-hydroxy-d-prolinol. Tetrahedron Lett 2020. [DOI: 10.1016/j.tetlet.2020.152081] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
|
8
|
Harit VK, Ramesh NG. A common strategy towards the synthesis of 1,4-dideoxy-1,4-imino-l-xylitol, deacetyl (+)-anisomycin and amino-substituted piperidine iminosugars. Carbohydr Res 2020; 492:107988. [PMID: 32387805 DOI: 10.1016/j.carres.2020.107988] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 03/17/2020] [Accepted: 03/17/2020] [Indexed: 12/15/2022]
Abstract
A strategy towards the synthesis of three different target molecules, namely 1,4-dideoxy-1,4-imino-l-xylitol, deacetyl (+)-anisomycin and amino-substituted piperidine iminosugars, molecules of potential biological and medicinal significance, is reported from a common amino-vicinal diol intermediate derived from tri-O-benzyl-d-glucal. Construction of the key pyrrolidine ring present in 1,4-dideoxy-1,4-imino-l-xylitol and (+)-anisomycin was a consequence of thermodynamically driven concomitant intramolecular nucleophilic addition reaction of the amino group to the resultant aldehyde obtained by oxidative cleavage of the amino-vicinal diol. Alternatively, double nucleophilic substitution on an amino-diol, after mesylation, with various amines delivered amino-substituted piperidine iminosugars in good yields.
Collapse
Affiliation(s)
- Vimal Kant Harit
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, 110016, India
| | - Namakkal G Ramesh
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, 110016, India.
| |
Collapse
|
9
|
Salunke RV, Ramesh NG. Divergent Synthesis of Amino-Substituted Indolizidine Alkaloids, Decahydropyrazino[2,1,6-cd]pyrrolizine Triols, and (-)-Pochonicine Stereoisomers. European J Org Chem 2020. [DOI: 10.1002/ejoc.202000194] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Rahul Vilas Salunke
- Department of Chemistry; Indian Institute of Technology Delhi; Hauz Khas; 110016 New Delhi - India
| | - Namakkal G. Ramesh
- Department of Chemistry; Indian Institute of Technology Delhi; Hauz Khas; 110016 New Delhi - India
| |
Collapse
|
10
|
Mishra UK, Ramesh NG. A glycal based approach to the synthesis of (+)-bulgecinine, 3-hydroxy-2,5-dihydroxymethylpyrrolidine and 2-oxapyrrolizidin-3-one. Carbohydr Res 2020; 489:107931. [PMID: 32088502 DOI: 10.1016/j.carres.2020.107931] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Revised: 01/29/2020] [Accepted: 01/29/2020] [Indexed: 11/25/2022]
Abstract
A glycal based synthesis of (+)-bulgecinine, 3-hydroxy-2,5-dihydroxymethylpyrrolidine and 2-oxapyrrolizidin-3-ones proceeding through a common intermediate is reported. The key step in the work presented here is a two-step conversion of 4,6-di-O-benzyl-d-glucal to 2,3-dideoxy-2-tosylamido-d-glucose. This manuscript reports the first carbohydrate based approach to the synthesis of (+)-bulgecinine and the whole sequence has been accomplished with complete stereochemical integrity without the formation of mixture of products in any of these steps.
Collapse
Affiliation(s)
- Umesh K Mishra
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, 110016, India
| | - Namakkal G Ramesh
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, 110016, India.
| |
Collapse
|
11
|
Harit VK, Ramesh NG. Ring closing metathesis (RCM) approach to the synthesis of conduramine B-2, ent-conduramine F-2, aminocyclopentitol and trihydroxyazepane. Org Biomol Chem 2019; 17:5951-5961. [PMID: 31166343 DOI: 10.1039/c9ob01010f] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The syntheses of conduramine B-2, ent-conduramine F-2, aminocyclopentitol and trihydroxyazepane were accomplished from a common precursor, through a divergent approach using ring closing metathesis (RCM) as the key step. Tri-O-benzyl-d-glucal was converted to 3,4,6-tri-O-benzyl-1,2-dideoxy-2-iodo-1-p-toluenesulfonamido-α-d-mannose. Exposure to NaBH4 in MeOH resulted in a facile 1,2-transposition of the -NHTs group with concomitant glycosylation to give methyl 3,4,6-tri-O-benzyl-2-deoxy-2-p-toluenesulfonamido-β-d-glucoside, which was converted into methyl 6-deoxy-6-iodo-glucoside in three steps. Zinc-mediated Vasella's rearrangement proceeded smoothly to give the pluripotent formyl-olefin, possessing both electrophilic and nucleophilic sites, which was used as a common precursor in our diversity-oriented approach. Vinylation of the carbonyl group followed by RCM and subsequent deprotection resulted in the successful synthesis of conduramine B-2 and ent-conduramine F-2 for the first time. On the other hand, the Wittig reaction of the formyl-olefin affords the diene that undergoes Grubbs' I catalyzed RCM and deprotection/reduction to provide 3-amino-cyclopentan-1,2-diol. Utilizing the nucleophilic site at the nitrogen of the common precursor, base mediated N-allylation was carried out to obtain the corresponding diene that underwent a smooth RCM to afford trihydroxyazepane.
Collapse
Affiliation(s)
- Vimal Kant Harit
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi - 110016, India.
| | | |
Collapse
|
12
|
Harit VK, Ramesh NG. Correction: Ring closing metathesis (RCM) approach to the synthesis of conduramine B-2, ent-conduramine F-2, aminocyclopentitol and trihydroxyazepane. Org Biomol Chem 2019; 17:6506. [DOI: 10.1039/c9ob90109d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Correction for ‘Ring closing metathesis (RCM) approach to the synthesis of conduramine B-2, ent-conduramine F-2, aminocyclopentitol and trihydroxyazepane’ by Vimal Kant Harit et al., Org. Biomol. Chem., 2019, 17, 5951–5961.
Collapse
Affiliation(s)
- Vimal Kant Harit
- Department of Chemistry
- Indian Institute of Technology Delhi
- New Delhi – 110016
- India
| | - Namakkal G. Ramesh
- Department of Chemistry
- Indian Institute of Technology Delhi
- New Delhi – 110016
- India
| |
Collapse
|
13
|
Santhanam V, Pant P, Jayaram B, Ramesh NG. Design, synthesis and glycosidase inhibition studies of novel triazole fused iminocyclitol-δ-lactams. Org Biomol Chem 2019; 17:1130-1140. [DOI: 10.1039/c8ob03084g] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Synthesis of novel triazole fused iminocyclitol-δ-lactams, from tri-O-benzyl-d-glucal, involving intermolecular [3 + 2]cycloaddition and intramolecular lactamisation reactions as key steps is described.
Collapse
Affiliation(s)
- Venkatesan Santhanam
- Department of Chemistry
- Indian Institute of Technology Delhi
- New Delhi – 110016
- India
| | - Pradeep Pant
- Department of Chemistry
- Indian Institute of Technology Delhi
- New Delhi – 110016
- India
| | - B. Jayaram
- Department of Chemistry
- Indian Institute of Technology Delhi
- New Delhi – 110016
- India
| | - Namakkal G. Ramesh
- Department of Chemistry
- Indian Institute of Technology Delhi
- New Delhi – 110016
- India
| |
Collapse
|
14
|
Harit VK, Ramesh NG. A Chiron Approach to Diversity-Oriented Synthesis of Aminocyclitols, (−)-Conduramine F-4 and Polyhydroxyaminoazepanes from a Common Precursor. J Org Chem 2016; 81:11574-11586. [DOI: 10.1021/acs.joc.6b01790] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Vimal Kant Harit
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| | - Namakkal G. Ramesh
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| |
Collapse
|
15
|
|
16
|
Abstract
A review on the syntheses and biological activities of unnatural glycomimetics highlighting the effect of replacement of hydroxyl groups of natural iminosugars by amino functionalities is presented.
Collapse
Affiliation(s)
- Vimal Kant Harit
- Department of Chemistry
- Indian Institute of Technology Delhi
- New Delhi - 110016
- India
| | - Namakkal G. Ramesh
- Department of Chemistry
- Indian Institute of Technology Delhi
- New Delhi - 110016
- India
| |
Collapse
|
17
|
|
18
|
Jaiswal M, Lale S, Ramesh NG, Koul V. Synthesis and characterization of positively charged interpenetrating double-network hydrogel matrices for biomedical applications. REACT FUNCT POLYM 2013. [DOI: 10.1016/j.reactfunctpolym.2013.07.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
19
|
|
20
|
Ganesan M, Salunke RV, Singh N, Ramesh NG. Protecting group directed diversity during Mitsunobu cyclization of a carbohydrate derived diamino triol. Synthesis of novel bridged bicyclic and six-membered iminocyclitols. Org Biomol Chem 2013. [DOI: 10.1039/c2ob27000e] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
|
21
|
Martı́nez-Montero S, Fernández S, Sanghvi YS, Chattopadhyaya J, Ganesan M, Ramesh NG, Gotor V, Ferrero M. Design and Divergent Synthesis of Aza Nucleosides from a Chiral Imino Sugar. J Org Chem 2012; 77:4671-8. [DOI: 10.1021/jo3004452] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Saúl Martı́nez-Montero
- Departamento de Quı́mica Orgánica e Inorgánica
and Instituto Universitario de Biotecnologı́a de Asturias, Universidad de Oviedo, 33006 Oviedo
(Asturias), Spain
- Program of Bioorganic Chemistry, Institute
of Cell and
Molecular Biology, Biomedical Centre, Uppsala University, SE-75123 Uppsala, Sweden
| | - Susana Fernández
- Departamento de Quı́mica Orgánica e Inorgánica
and Instituto Universitario de Biotecnologı́a de Asturias, Universidad de Oviedo, 33006 Oviedo
(Asturias), Spain
| | - Yogesh S. Sanghvi
- Rasayan Inc., 2802 Crystal Ridge Road, Encinitas, California
92024-6615, United
States
| | - Jyoti Chattopadhyaya
- Program of Bioorganic Chemistry, Institute
of Cell and
Molecular Biology, Biomedical Centre, Uppsala University, SE-75123 Uppsala, Sweden
| | - Muthupandian Ganesan
- Department of Chemistry, Indian Institute of Technology, Delhi, Hauz Khas, New Delhi 110016, India
| | - Namakkal G. Ramesh
- Department of Chemistry, Indian Institute of Technology, Delhi, Hauz Khas, New Delhi 110016, India
| | - Vicente Gotor
- Departamento de Quı́mica Orgánica e Inorgánica
and Instituto Universitario de Biotecnologı́a de Asturias, Universidad de Oviedo, 33006 Oviedo
(Asturias), Spain
| | - Miguel Ferrero
- Departamento de Quı́mica Orgánica e Inorgánica
and Instituto Universitario de Biotecnologı́a de Asturias, Universidad de Oviedo, 33006 Oviedo
(Asturias), Spain
| |
Collapse
|
22
|
|
23
|
Ganesan M, Madhukarrao RV, Ramesh NG. Design and synthesis of new amino-modified iminocyclitols: selective inhibitors of α-galactosidase. Org Biomol Chem 2010; 8:1527-30. [DOI: 10.1039/b926123k] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
24
|
Majumder AB, Ramesh NG, Gupta MN. A lipase catalyzed condensation reaction with a tricyclic diketone: yet another example of biocatalytic promiscuity. Tetrahedron Lett 2009. [DOI: 10.1016/j.tetlet.2009.06.108] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
25
|
|
26
|
Nagaraj P, Ramesh NG. InCl3-Catalyzed Rapid 1,3-Alkoxy Migration in Glycal Ethers: Stereoselective Synthesis of Unsaturated α-O-Glycosides and an α,α-(1→1)-Linked Disaccharide. European J Org Chem 2008. [DOI: 10.1002/ejoc.200800453] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
27
|
|
28
|
Kumar V, Ramesh NG. Corrigendum to: “A glycal approach towards an efficient and stereodivergent synthesis of polyhydroxypyrrolidines”. Tetrahedron 2006. [DOI: 10.1016/j.tet.2006.02.058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
29
|
Mondal K, Ramesh NG, Roy I, Gupta MN. Enhancing the synthetic utility of aldolase antibody 38C2. Bioorg Med Chem Lett 2006; 16:807-10. [PMID: 16321532 DOI: 10.1016/j.bmcl.2005.11.019] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2005] [Revised: 10/25/2005] [Accepted: 11/08/2005] [Indexed: 11/21/2022]
Abstract
Three-phase partitioning (TPP) treated aldolase antibody 38C2 was evaluated for aldol reaction between p-nitrobenzaldehyde and acetone to give 4-(4'-nitrophenyl)-4-hydroxy-2-butanone. While TPP-treated 38C2 transformed 65% of p-nitrobenzaldehyde, the untreated 38C2 gave only 24% transformation in 18 h at 25 degrees C. However, since TPP-treated 38C2 also gave an additional (unidentified) product, its synthetic utility was limited. Crosslinked aggregate of 38C2, however, gave the biocatalyst which gave a single product and could be reused at 40 degrees C five times without loss of activity.
Collapse
Affiliation(s)
- Kalyani Mondal
- Chemistry Department, Indian Institute of Technology, Delhi, Hauz Khas, New Delhi 110016, India
| | | | | | | |
Collapse
|
30
|
|
31
|
Kumar V, Ramesh NG. Iodine catalyzed one-pot diamination of glycals with chloramine-T: a new approach to 2-amino-β-glycosylamines for applications in N-glycopeptide synthesis. Chem Commun (Camb) 2006:4952-4. [PMID: 17136258 DOI: 10.1039/b612151a] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Iodine catalyzes a facile one-pot direct diamination of glycals with chloramine-T to afford stereoselectively 2-amino-beta-glycosylamine derivatives that serve as convenient precursors for the synthesis of N-linked glycopeptides.
Collapse
Affiliation(s)
- Vipin Kumar
- Department of Chemistry, Indian Institute of Technology - Delhi, Hauz Khas, New Delhi - 110016, India
| | | |
Collapse
|
32
|
Ramesh NG, Hassner A. Studies Towards the Synthesis of Functionalized Medium-Sized Carbocyclic and Fused Bicyclic Systems by Alkoxy Radical Fragmentation (ARF). European J Org Chem 2005. [DOI: 10.1002/ejoc.200400763] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
33
|
Hassner A, Ramesh NG. Photochemical Ring Opening of Tricyclic Hemiketals: Diastereoselective Construction of Functionalized Medium-Sized Carbocycles and a Diquinane. Synlett 2004. [DOI: 10.1055/s-2004-820044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
34
|
Ramesh NG, Bakkeren FJ, Groot DD, Passamonti U, Klunder AJ, Zwanenburg B. Asymmetric desymmetrization of pseudo-meso 5-hydroxy-endo-tricyclo[5.2.1.02,6]deca-4,8-dien-3-ones. Tetrahedron 2001. [DOI: 10.1016/s0040-4020(01)01007-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
35
|
Ramesh NG, Klunder AJ, Zwanenburg B. Regioselective electrophilic oxidation of a 5-amino- endo -tricyclo[5.2.1.0 2,6 ]decenyl enaminone. Synthesis of a novel heterocyclic compound. Tetrahedron Lett 2001. [DOI: 10.1016/s0040-4039(01)01636-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
36
|
Kita Y, Nambu H, Ramesh NG, Anilkumar G, Matsugi M. A Novel and Efficient Methodology for the C−C Bond Forming Radical Cyclization of Hydrophobic Substrates in Water. Org Lett 2001; 3:1157-60. [PMID: 11348183 DOI: 10.1021/ol010014p] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
[reaction: see text]. The combination of water-soluble radical initiator 2,2'-azobis[2-(2-imidazolin-2-yl)propane] (VA-061), water-soluble chain carrier 1-ethylpiperidine hypophosphite (EPHP), and surfactant cetyltrimethylammonium bromide (CTAB) was found to be the most suitable condition for effective radical cyclization in water for a variety of hydrophobic substrates.
Collapse
Affiliation(s)
- Y Kita
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6, Yamada-oka, Suita, Osaka 565-0871, Japan.
| | | | | | | | | |
Collapse
|
37
|
Arisawa M, Ramesh NG, Nakajima M, Tohma H, Kita Y. Hypervalent iodine(III)-induced intramolecular cyclization of alpha-(aryl)alkyl-beta-dicarbonyl compounds: a convenient synthesis of benzannulated and spirobenzannulated compounds. J Org Chem 2001; 66:59-65. [PMID: 11429930 DOI: 10.1021/jo000953f] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A novel hypervalent iodine(III)-induced direct intramolecular cyclization of alpha-(aryl)alkyl-beta-dicarbonyl compounds has been described. Both meta- and para-substituted phenol ether derivatives containing acyclic or cyclic 1,3-dicarbonyl moieties at the side chain undergo this reaction in a facile manner. The reactions afford benzannulated and spirobenzannulated compounds that are of biological importance. The reaction is found to be general, mild, and high yielding. The mechanism of the reaction has been shown to involve a cation radical intermediate.
Collapse
Affiliation(s)
- M Arisawa
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamada-oka, Suita, Osaka 565-0871, Japan
| | | | | | | | | |
Collapse
|
38
|
Ramesh NG, Klunder AJH, Zwanenburg B. Enantioselective Synthesis of 4-Acetylaminocyclopent-2-en-1-ols from Tricyclo[5.2.1.0(2,6)]decenyl Enaminones. Precursors for 5'-Norcarbocyclic Nucleosides and Related Antiviral Compounds. J Org Chem 1999; 64:3635-3641. [PMID: 11674491 DOI: 10.1021/jo982498h] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
An efficient synthesis of both (1S,4R) and (1R,4S)-4-N-acetylamino-1-benzoylcyclopent-2-enes 33 has been accomplished starting from enantiopure 5-(1'-phenylethylamino)-endo-tricyclo[5.2.1.0(2,6)]deca-4,8-dien-3-ones 14 and 15. N-Acetylation of both 15 and 14 followed by single electron-transfer reduction using lithium in liquid ammonia afforded diastereomeric mixtures of beta-amino ketones 26 and 27 and of ent-26 and ent-27 in high yields and with high diastereoselectivity. In this reduction process, the enaminone double bond is reduced with the concomitant removal of the alpha-methylbenzyl group as the chiral auxiliary. Thermolysis of the respective diastereomic mixtures of 26 and 27 in the gas phase (FVT) or in solution afforded 4-N-acetylaminocyclopent-2-ene-1-ones 30 in high optical and chemical yields. Acidic hydrolysis of (+)-30 gave (R)-(+)-4-aminocyclopentenone 31 as its hydrochloride. Stereoselective reduction of 30 using sodium borohydride and cerium chloride heptahydrate furnished amido alcohol 32, which was isolated and characterized as its benzoyl derivative 33.
Collapse
Affiliation(s)
- Namakkal G. Ramesh
- Department of Organic Chemistry, NSR Center for Molecular Structure, Design and Synthesis, University of Nijmegen, Toernooiveld, 6525 ED Nijmegen, The Netherlands
| | | | | |
Collapse
|
39
|
Arisawa M, Utsumi S, Nakajima M, Ramesh NG, Tohma H, Kita Y. An unexpected intermolecular chiral biaryl coupling reaction induced by a hypervalent iodine(III) reagent: synthesis of potential precursor for ellagitannin. Chem Commun (Camb) 1999. [DOI: 10.1039/a809680e] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
40
|
Ramesh NG, Klunder AJ, Zwanenburg B. Enantioselective synthesis of 4-aminocyclopent-2-ene-1-one from tricyclo[5.2.1.02,6]decenyl enaminones. Tetrahedron Lett 1998. [DOI: 10.1016/s0040-4039(97)10820-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
|
41
|
Ramesh NG, Iio K, Okajima A, Akai S, Kita Y. A strong-base induced [4+2] cycloaddition of homophthalic anhydrides with enolizable enones: a direct and efficient synthesis of peri-hydroxy aromatic compounds. Chem Commun (Camb) 1998. [DOI: 10.1039/a807095d] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
42
|
Yechezkel T, Ghera E, Ramesh NG, Hassner A. Asymmetric synthesis of substituted cyclopentanes via Michael initiated ring closure reactions. ACTA ACUST UNITED AC 1996. [DOI: 10.1016/0957-4166(96)00301-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|