A unified approach to sesquiterpenes sharing trimethyl(p-tolyl) cyclopentanes: Formal total synthesis of (±)-laurokamurene B
作者:Mrinal K. Das、Bidyut K. Dinda、Vishnumaya Bisai
DOI:10.1016/j.tetlet.2019.05.032
日期:2019.8
A unified approach to the sesquiterpenoids sharing common trimethyl(p-tolyl) cyclopentane skeleton has been disclosed via a key Stork-Danheiser sequence on a cyclopentane based vinylogous ester with aryl Grignard reagent followed by α-methylation strategy. The strategy is eventually applied to the concise formaltotalsynthesis of (±)-laurokamurene B (1b) in only 5 steps with 45.4% overall yield.
The enantioselectivehydrogenation of endocyclic enones has been a historical problem for homogeneous catalysis. We herein report an efficient method to reduce endocyclic enones with molecular hydrogen. Catalyzed by a rhodium/Zhaophos complex, a variety of enones with five‐, six‐ or seven‐member ring were hydrogenated with high enantioselectivity (92%—99% ee). Excellent chemo‐ and enantioselectivity