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Chahboun R, Botubol-Ares JM, Durán-Peña MJ, Jiménez F, Alvarez-Manzaneda R, Alvarez-Manzaneda E. Deconjugative α-Alkylation of Cyclohexenecarboxaldehydes: An Access to Diverse Terpenoids. J Org Chem 2021; 86:8742-8754. [PMID: 34128666 PMCID: PMC8901105 DOI: 10.1021/acs.joc.1c00560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A general and efficient method for the deconjugative α-alkylation of α,β-unsaturated aldehydes promoted by a synergistic effect between tBuOK and NaH, which considerably increases the reaction rate under mild conditions, is reported. The β,γ-unsaturated aldehyde, resulting from the α-alkylation, is transformed in high yield into the corresponding allyl acetate via a lead(IV) acetate-mediated oxidative fragmentation. This strategy could be used for the construction of the carbon skeleton of a wide variety of alkyl or arylterpenoids.
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Affiliation(s)
- Rachid Chahboun
- Departamento de Química Orgánica, Facultad de Ciencias, Instituto de Biotecnología, Universidad de Granada, 18071 Granada, Spain
| | - José Manuel Botubol-Ares
- Departamento de Química Orgánica, Facultad de Ciencias, Campus Universitario Río San Pedro s/n, Torre Sur, 4a planta, University of Cádiz, Puerto Real, 11510 Cádiz, Spain
| | - María Jesús Durán-Peña
- Departamento de Química Orgánica, Facultad de Ciencias, Campus Universitario Río San Pedro s/n, Torre Sur, 4a planta, University of Cádiz, Puerto Real, 11510 Cádiz, Spain
| | - Fermín Jiménez
- Departamento de Química Orgánica, Facultad de Ciencias, Instituto de Biotecnología, Universidad de Granada, 18071 Granada, Spain
| | - Ramón Alvarez-Manzaneda
- Área de Química Orgánica, Departamento de Química y Física, Universidad de Almería, 04120 Almería, Spain
| | - Enrique Alvarez-Manzaneda
- Departamento de Química Orgánica, Facultad de Ciencias, Instituto de Biotecnología, Universidad de Granada, 18071 Granada, Spain
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2
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Bouanou H, Gil JA, Alvarez-Manzaneda R, Chahboun R, Alvarez-Manzaneda E. Oxidative Coupling of (-)-Sclareol and Related Diols Leading to Oxepane Terpenoids. J Org Chem 2016; 81:10002-10008. [PMID: 27689238 DOI: 10.1021/acs.joc.6b01834] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Treatment of (-)-sclareol and related compounds with lead tetraacetate affords tetracyclic compounds bearing a 2,8-dioxabicyclo[5.2.0]nonane moiety with complete regio- and stereoselectivity. This process, which is also applicable to 1,5-diols with a similar substitution pattern, facilitates the development of efficient syntheses toward oxepane terpenoids, such as aplysistatin derivatives.
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Affiliation(s)
- Hanane Bouanou
- Departamento de Química Orgánica, Facultad de Ciencias, Universidad de Granada , 18071 Granada, Spain
| | - Juan A Gil
- Departamento de Química Orgánica, Facultad de Ciencias, Universidad de Granada , 18071 Granada, Spain
| | - Ramón Alvarez-Manzaneda
- Área de Química Orgánica, Departamento de Química y Física, Universidad de Almería , 04120 Almería, Spain
| | - Rachid Chahboun
- Departamento de Química Orgánica, Facultad de Ciencias, Universidad de Granada , 18071 Granada, Spain
| | - Enrique Alvarez-Manzaneda
- Departamento de Química Orgánica, Facultad de Ciencias, Universidad de Granada , 18071 Granada, Spain
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von Wachenfeldt H, Strand D. Synthesis of Formylsilanes through Oxidative Cleavage of α-Silyl Glycols. J Org Chem 2013; 78:12268-73. [DOI: 10.1021/jo402123j] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Henrik von Wachenfeldt
- Centre
for Analysis and Synthesis,
Department of Chemistry, Lund University, PO Box 124, S-221 00 Lund, Sweden
| | - Daniel Strand
- Centre
for Analysis and Synthesis,
Department of Chemistry, Lund University, PO Box 124, S-221 00 Lund, Sweden
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Zhang HJ, Priebbenow DL, Bolm C. Acylsilanes: valuable organosilicon reagents in organic synthesis. Chem Soc Rev 2013; 42:8540-71. [DOI: 10.1039/c3cs60185d] [Citation(s) in RCA: 168] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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5
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Radical cyclizations of acylsilanes in the synthesis of (+)-swainsonine and formal synthesis of (−)-epiquinamide. Tetrahedron 2011. [DOI: 10.1016/j.tet.2010.12.048] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Chang CC, Kuo YH, Tsai YM. The synthesis of carbohydrate-derived acylsilanes and their intramolecular free radical cyclizations with the formation of polyoxygenated cyclopentanes. Tetrahedron Lett 2009. [DOI: 10.1016/j.tetlet.2009.04.032] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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7
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Rontani JF, Koblízek M. Regiospecific enzymatic oxygenation of cis-vaccenic acid in the marine phototrophic bacterium Erythrobacter sp. strain MG3. Lipids 2008; 43:1065-74. [PMID: 18818965 DOI: 10.1007/s11745-008-3237-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2008] [Accepted: 09/03/2008] [Indexed: 10/21/2022]
Abstract
The fatty acid composition of the marine phototrophic bacterium Erythrobacter sp. strain MG3 was analysed. The involvement of an unusual enzymatic peroxidation of the allylic carbon 10 of cis-vaccenic acid in this strain was confirmed. This process, which seems to be a characteristic of some aerobic and anaerobic phototrophic bacteria, appeared to also act on the allylic carbon 10 of octadeca-5,11-dienoic acid. Enzymatic degradation of 10-hydroperoxyoctadec-11(cis)-enoic acid resulting from the peroxidation of cis-vaccenic acid mainly involves reduction to the corresponding hydroxy acid (probably catalysed by peroxygenases) and cleavage to the corresponding oxoacid, which is then biohydrogenated. Abiotic degradation of this hydroperoxide involves allylic rearrangement to 10-hydroperoxyoctadec-11(trans)-enoic and 12-hydroperoxyoctadec-10(trans)-enoic acids and cyclisation to the very unusual 7,10-epoxyoctadec-11(cis)-enoic acid. Several tests carried out at different periods of growth and under different growth conditions allowed to show that the induction of this enzymatic peroxidation process strongly depends on the physiological state of the cells and is enhanced during C-limitation and at low temperatures.
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Affiliation(s)
- J-F Rontani
- Laboratoire de Microbiologie de Géochimie et d'Ecologie Marines (UMR 6117), 13288, Marseille, France.
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8
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Ueng SH, Chen MJ, Chu SF, Shao YF, Fan GT, Chang SY, Tsai YM. The Scope and Limitations of 1,3-Stannyl Shift-Promoted Intramolecular Cyclizations of α-Stannyl Radicals with a Formyl Group. J Org Chem 2006; 71:1502-12. [PMID: 16468799 DOI: 10.1021/jo052176v] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Alpha-tributylstannyl radicals can be generated from the corresponding bromides or xanthates. These radicals undergo efficient intramolecular 1,5-cyclizations with a formyl group. The resulting beta-stannyl alkoxy radicals proceed through a 1,3-stannyl shift from carbon to oxygen to afford beta-stannyloxy radicals. This novel rearrangement is most likely irreversible and serves as a driving force to promote the cyclizations. Although the cyclization rates can be accelerated when the formyl group carries alpha-dimethyl substituents, unfortunately beta-scission of the alkoxy radicals becomes competitive with the 1,3-stannyl shift. The beta-stannyloxy radicals can be employed in further cyclizations to obtain tandem cyclization products.
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Affiliation(s)
- Shau-Hua Ueng
- Department of Chemistry, National Taiwan University, Taipei, Taiwan 106, Republic of China
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Yu Y, Feng S, Feng D. An ab Initio Study on Thermal Rearrangement Reactions of 1-Silylprop-2-en-1-ol H3SiCH(OH)CHCH2. J Phys Chem A 2005; 109:3663-8. [PMID: 16839032 DOI: 10.1021/jp045892u] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The thermal rearrangement reactions of 1-silylprop-2-en-1-ol H3SiCH(OH)CH=CH2 were studied by ab initio calculations at the G2(MP2) and G3 levels. The reaction mechanisms were revealed through ab initio molecular orbital theory. On the basis of the MP2(full)/6-31G(d) optimized geometries, harmonic vibrational frequencies of various stationary points were calculated. The reaction paths were investigated and confirmed by intrinsic reaction coordinate (IRC) calculations. The results show that the thermal rearrangements of H3SiCH(OH)CH=CH2 happen in two ways. One is via the Brook rearrangement reactions (reaction A), and the silyl group migrates from carbon atom to oxygen atom passing through a double three-membered ring transition state, forming allyloxysilane CH2=CHCH2OSiH3. In the other, the reactant undergoes a dyotropic rearrangement; the hydroxyl group migrates from carbon atom to silicon atom coupled with a simultaneous migration of a hydrogen atom from silicon atom to carbon atom, forming allylsilanol CH2=CHCH2SiH2OH (reaction B). The barriers for reactions A and B were computed to be 343.5 and 203.7 kJ/mol, respectively, at the G3 level. The changes of the thermodynamic functions, entropy (DeltaS), entropy (DeltaS(doubledagger)) for the transition state, enthalpy (DeltaH), and free energy (DeltaG) were calculated by using the MP2(full)/6-31G(d) optimized geometries, and harmonic vibrational frequencies of reactants, transition states, and products with statistical mechanical methods, and equilibrium constant K(T) and reaction rate constant k(T) in canonical variational transition-state theory (CVT) with centrifugal-dominant small-curvature tunneling approximation (SCT) were calculated over a temperature range 400-1300 K. The conventional transition-state theory (TST) rate constants were also calculated for the purposes of comparison. The influences of the vinyl group attached to the center carbon of the alpha-silyl alcohols on reactions were discussed.
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Affiliation(s)
- Yongming Yu
- School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, P.R. China
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10
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The study of intramolecular tandem radical cyclizations of acylsilanes with radicalphiles attached on silicon. Tetrahedron 2005. [DOI: 10.1016/j.tet.2004.12.053] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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11
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Yu Y, Feng S. An ab Initio Study on [1,2] Rearrangement Reactions of Silylmethanol H3SiCH2OH. J Phys Chem A 2004. [DOI: 10.1021/jp048197v] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Yongming Yu
- School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, P.R. China, and School of Chemistry and Chemical Engineering, Qingdao University, Qingdao 266071, P.R. China
| | - Shengyu Feng
- School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, P.R. China, and School of Chemistry and Chemical Engineering, Qingdao University, Qingdao 266071, P.R. China
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Huang CH, Chang SY, Wang NS, Tsai YM. The application of intramolecular radical cyclizations of acylsilanes in the regiospecific formation of cyclic silyl enol ethers. J Org Chem 2001; 66:8983-91. [PMID: 11749631 DOI: 10.1021/jo010883s] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Acylsilanes with terminal alpha-stannyl bromide or xanthate functionalities are prepared. Alpha-stannyl radicals generated from these acylsilanes undergo intramolecular cyclizations to give cyclic silyl enol ethers regiospecifically. The radical processes involve radical cyclization, Brook rearrangement, and beta-fragmentation in sequence. A tributylstannyl group serves as the radical leaving group. The newly formed sigma-bond and pi-bond are located between the same two carbon atoms. This approach is limited to the formation of five-membered rings. In another route, omega-bromo-alpha-phenylsulfonylacylsilanes are synthesized. The radical cyclizations of these alpha-sulfonylacylsilanes also give cyclic silyl enol ethers. The phenylsulfonyl moiety is the radical leaving group in this system. Furthermore, the newly formed sigma-bond and pi-bond are located at adjacent positions sharing a single carbon atom. The latter approach is effective for both five- and six-membered ring formation.
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Affiliation(s)
- C H Huang
- Department of Chemistry, National Taiwan University, Taipei, Taiwan 106, Republic of China
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Patrocínio AF, Moran PJS. A SIMPLE METHOD FOR MILD OXIDATION OF α-HYDROXYSILANES TO PROVIDE AROYLSILANES. SYNTHETIC COMMUN 2001. [DOI: 10.1081/scc-100105124] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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