A flexible asymmetric synthesis of both enantiomers of euphopilolide (1) and jolkinolide E (2) [(+)-and (−)-1, (+)-and (−)-2] has been accomplished. This synthesis features an intramolecular oxa-Pauson-Khand reaction (o-PKR) to expeditiously construct the challenging tetracyclic [6.6.6.5] abietane-type diterpene framework, elegantly showcasing the complexity-generating features of o-PKR synthetic methodology
Total synthesis of (±)−jolkinolide A, B, and E utilizing a new mild esterification followsd by intramolecular Wittig-Horner reaction
作者:Shigeo Katsumura、Akihiko Kimura、Sachihiko Isoe
DOI:10.1016/0040-4020(89)80132-2
日期:1989.1
Jolkinolide A, B, and E were efficiently synthesized from 9-methoxy-carbonyl-4,4,10-trimethyl-Δ6-8-octalone 8 through Δ8(14)-podocalpen-13-one . A new synthetic method of γ-ylidenbutenolide consisting of mild esterification and the succeeding intramolecular Wittig-Horner reaction of α-diketone was developed.
AN EFFICIENT SYNTHESIS OF JOLKINOLIDE E INVOLVING THE BUTENOLIDE RING FORMATION BY INTRAMOLECULAR WITTIG REACTION
作者:Shigeo Katsumura、Sachihiko Isoe
DOI:10.1246/cl.1982.1689
日期:1982.10.5
A synthesis of jolkinolide E from the bicyclic enone 3 using intramolecularWittigreaction is described. In this synthesis a facile esterification method by means of a mixed anhydride of trichloroacetic acid catalyzed by DMAP, which culminates in the effective synthesis of the α,β,γ-trisubstituted butenolide ring, is also described.