1
|
Chan KH, Groves JT. Concise Modular Synthesis and NMR Structural Determination of Gallium Mycobactin T. J Org Chem 2021; 86:15453-15468. [PMID: 34699221 DOI: 10.1021/acs.joc.1c01966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A modular synthesis of mycobactin T and its N-acetyl analogue is reported in a route that facilitates permutation of the lipid tails. A key feature is the generation of N(α)-Cbz-N(ε)-benzyloxy-N(ε)-Boc-lysine (A4) with methyl(trifluoromethyl)dioxirane in 59% yield. Selective hydroxamate N-acylation was achieved with acyl fluorides, enabling installation of lipids tails in the final step. O-Benzyl-dehydrocobactin T (B4) was prepared by modifying a known five-step sequence with an overall yield of 49%. 2-Hydroxyphenyl-4-carboxyloxazoline (C3) was prepared from 2-hydroxybenzoic acid and l-serine methyl ester in three steps with an overall yield of 55%. Ester coupling of A4 and B4 with EDCI afforded MbI-1 in 73% yield. Catalytic hydrogenation with Pd/BaSO4 and 50 psi of H2 simultaneously effected alkene reduction and debenzylation to afford MbI-2 in 96% yield. Fragment C3 was converted into acyl fluoride C4, which coupled with MbI-2 to afford MbI-3 in 51% yield. Finally, Boc-removal with HCl/EtOAc and treatment of the resultant hydroxylamine with stearyl fluoride furnished mycobactin T in 65% yield. Overall, the yield is 4% over 14 steps. The gallium mycobactin T-N-acetyl derivative (GaMbT-NAc) structure was determined by 1H NMR. The structure shows an octahedral Ga and two internal hydrogen bonds between peptidic N-Hs and two of the oxygen atoms coordinating Ga.
Collapse
Affiliation(s)
- Kiat Hwa Chan
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States.,Division of Science, Yale-NUS College, 16 College Avenue West, Singapore 138527, Singapore
| | - John T Groves
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| |
Collapse
|
2
|
A mild and efficient method for the selective cleavage of primary p-methoxybenzyl protecting group of saccharides by Co2(CO)8–Me2PhSiH–CO system. Tetrahedron Lett 2015. [DOI: 10.1016/j.tetlet.2015.07.051] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
3
|
Aponte JC, Hammond GB, Xu B. TBAF-Mediated Aldol Reaction of β-Allenoates: Regio- and Stereoselective Synthesis of (2E,4E)-4-Carbinol Alkadienoates. J Org Chem 2009; 74:4623-5. [DOI: 10.1021/jo900567m] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- José C. Aponte
- Department of Chemistry, University of Louisville, Louisville, Kentucky 40292
| | - Gerald B. Hammond
- Department of Chemistry, University of Louisville, Louisville, Kentucky 40292
| | - Bo Xu
- Department of Chemistry, University of Louisville, Louisville, Kentucky 40292
| |
Collapse
|
4
|
Annese C, D'Accolti L, Dinoi A, Fusco C, Gandolfi R, Curci R. Concerning the Reactivity of Dioxiranes. Observations from Experiments and Theory. J Am Chem Soc 2008; 130:1197-204. [DOI: 10.1021/ja075068u] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Cosimo Annese
- Dipartimento Chimica, Università di Bari, CNR.-ICCOM, v. Amendola 173, I-70126 Bari, Italy, and Dipartimento di Chimica Organica, Università di Pavia, v.le Taramelli 10, 27100 Pavia, Italy
| | - Lucia D'Accolti
- Dipartimento Chimica, Università di Bari, CNR.-ICCOM, v. Amendola 173, I-70126 Bari, Italy, and Dipartimento di Chimica Organica, Università di Pavia, v.le Taramelli 10, 27100 Pavia, Italy
| | - Anna Dinoi
- Dipartimento Chimica, Università di Bari, CNR.-ICCOM, v. Amendola 173, I-70126 Bari, Italy, and Dipartimento di Chimica Organica, Università di Pavia, v.le Taramelli 10, 27100 Pavia, Italy
| | - Caterina Fusco
- Dipartimento Chimica, Università di Bari, CNR.-ICCOM, v. Amendola 173, I-70126 Bari, Italy, and Dipartimento di Chimica Organica, Università di Pavia, v.le Taramelli 10, 27100 Pavia, Italy
| | - Remo Gandolfi
- Dipartimento Chimica, Università di Bari, CNR.-ICCOM, v. Amendola 173, I-70126 Bari, Italy, and Dipartimento di Chimica Organica, Università di Pavia, v.le Taramelli 10, 27100 Pavia, Italy
| | - Ruggero Curci
- Dipartimento Chimica, Università di Bari, CNR.-ICCOM, v. Amendola 173, I-70126 Bari, Italy, and Dipartimento di Chimica Organica, Università di Pavia, v.le Taramelli 10, 27100 Pavia, Italy
| |
Collapse
|
5
|
Kreilein MM, Hofferberth JE, Hart AC, Paquette LA. Diosphenol-Based Approach to the A-Ring Functionalization of Advanced Taxol Precursors. J Org Chem 2006; 71:7329-36. [PMID: 16958527 DOI: 10.1021/jo061115+] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Several different approaches to the A-ring functionalization of an advanced, highly functionalized diosphenol precursor to Taxol are described. The first phase of the undertaking consists of an assessment of those reagents conducive to reaction at the enolic oxygen (silylation, methylation, allylation, and acylation). Transformations involving an alternative attack at the enol carbon center (bromination, selenation) have also been defined. Sodium borohydride reduction operates from the beta-face of C-14 as long as the C-1 hydroxyl is not protected so as to offer steric exclusion. Complications associated with various aspects of these methodological undertakings are addressed. The most advanced oxygenation achievements were realized by way of a noteworthy sequence involving epoxidation of the O-methyl ether, methanolysis under mildly acidic conditions, and regioselective oxidation of diol 38 to give 39.
Collapse
Affiliation(s)
- Matthew M Kreilein
- Evans Chemical Laboratories, Ohio State University, Columbus, Ohio 43210, USA
| | | | | | | |
Collapse
|