Enantioselective synthesis of an advanced intermediate to quassinoids
作者:Claude Spino、Noah Tu
DOI:10.1016/s0040-4039(00)73071-1
日期:1994.5
An optically pure advanced intermediate to the quassinoids was prepared via the diene-transmissive Diels-Alder cycloaddition strategy. The absolute stereochemistry of the intramolecular cycloaddition was controlled by a methyl and a t-butyldimethylsilyloxy group via a chair-like endo transition state.
Palladium-catalyzed cyclization of 8-bromo-2,8-nonadienoates proceeded stereoselectively to give 1-alpha-hydroxyvitamin D3 A-ring synthons in good yields.