Brief syntheses of (+)-blastmycinone and related γ-lactones from an asymmetrically dihydroxylated carboxylic ester

Article abstract of DOI:10.1016/S0040-4020(98)00687-5

A method for synthesizing optically active trans,trans-configurated α,β,γ-substituted γ-lactones is presented. Asymmetric hydroxylation of ester 8 with AD mix α (AD mix β) and subsequent dehydration provided butenolide S-6 (R-6). Conjugate addition of Li₂(Me₂PhSi)₂Cu(CN) to S-6 followed by alkylation of the resulting enolate led to the stereopure silyllactones 9-11. They furnished the title compounds after oxidative removal of the Me₂PhSi group.