Yamada K, Iwadare H, Mukaiyama T
Department of Applied Chemistry, Faculty of Science, Science University of Tokyo, Japan.
Chem Pharm Bull (Tokyo). 1997 Dec;45(12):1898-905. doi: 10.1248/cpb.45.1898.
Construction of the AB-ring system of the taxane framework via an A-ring annulation strategy was demonstrated by base-mediated intramolecular aldol reaction of (Z)-2,2-dimethyl-3-(1-methyl-2-oxopropylidene)cyclooctanone, affording the title compound, 1-hydroxy-8,11,11-trimethylbicyclo[5.3.1]undec-7-en-9-one. A cyclization precursor, the tetra-substituted (Z)-alkene, was prepared from the corresponding cyclooctanone derivative, 3-[(alpha,alpha- dimethylbenzyl)dimethylsiloxy]-2,2-dimethylcyclooctanone via a bicyclic alpha,beta-unsaturated lactone intermediate.
通过（Z）-2,2-二甲基-3-（1-甲基-2-氧代亚丙基）环辛酮的碱介导分子内羟醛反应，证明了通过A环环化策略构建紫杉烷骨架的AB环系统，得到标题化合物1-羟基-8,11,11-三甲基双环[5.3.1]十一碳-7-烯-9-酮。环化前体，即四取代的（Z）-烯烃，是由相应的环辛酮衍生物3-[(α,α-二甲基苄基)二甲基硅氧基]-2,2-二甲基环辛酮经双环α,β-不饱和内酯中间体制备而成。
