S-(+)-carvone as starting material in synthesis (part 4). Conjugate addition of cyanide and Grignard nucleophiles followed by annulation to functionalized decalones.
摘要:
Two conjugate addition/annulation methodologies for S-(+)-carvone are reported. The conjugate addition of Grignard reagents, followed by the Lewis acid catalyzed Michael reaction of the intermediate silyl enol ethers with MVK and cyclization of the diketones, gave decalones 2a-d stereoselectively and in good yield. The conjugate addition of cyanide anion followed by base catalyzed Robinson annulation with MVK and dehydration gave decalone 2e stereoselectively in very high yield.
S-(+)-carvone as starting material in synthesis (part 4). Conjugate addition of cyanide and Grignard nucleophiles followed by annulation to functionalized decalones.
作者:Anja A. Verstegen-Haaksma、Henk J. Swarts、Ben J.M. Jansen、Aede de Groot
DOI:10.1016/s0040-4020(01)89623-x
日期:1994.1
Two conjugate addition/annulation methodologies for S-(+)-carvone are reported. The conjugate addition of Grignard reagents, followed by the Lewis acid catalyzed Michael reaction of the intermediate silyl enol ethers with MVK and cyclization of the diketones, gave decalones 2a-d stereoselectively and in good yield. The conjugate addition of cyanide anion followed by base catalyzed Robinson annulation with MVK and dehydration gave decalone 2e stereoselectively in very high yield.
Total synthesis of drimane sesquiterpenes from S-(+)-carvone (part 5)
作者:Henk J. Swarts、Anja A. Verstegen-Haaksma、Ben J.M. Jansen、Aede de Groot
DOI:10.1016/s0040-4020(01)89624-1
日期:1994.1
Conjugateaddition of potassium cyanide to S-(+)-carvone followed by annulation with methylvinylketone nitrile 4 in high yield. Methylation of 4, removal of the isopropenyl group and the introduction of C-12 via formylation then gave the unsaturated keto lactone 21 which is an excellent intermediate in the total synthesis of drimane sesquiterpenes. This was demonstrated with the total synthesis of