Gold-catalyzed Hosomi–Sakurai type reaction for the total synthesis of herboxidiene

Abstract

Total synthesis of herboxidiene/GEX1A/TAN-1609 has been accomplished in the 22 longest linear sequences starting from 2-butyne-1,4-diol following our recently developed gold-catalyzed Hosomi–Sakurai type of reaction on lactols with allyltrimethyl silane and Stille cross coupling to assemble the advanced fragment. The synthesis of the C10–C19 fragment was accomplished by means of Sharpless epoxidation and asymmetric alkylation reactions starting from (R)-methyl lactate.