Acetogenin synthesis. Organocopper reagents, anions of 1,3-dithians and of protected cyanohydrins as intermediates in ketide side-chain synthesis

Abstract

The synthesis is reported of 3-s-butyl-4-methyl-3,6,8-trihydroxy-3,4-dihydroisocoumarin (1a) and 3-(1-methylprop-1-enyl)-4-methyl-3,6,8-trihydroxy-3,4-dihydroisocoumarin (1b) using organocopper reagents and anions of 1,3-dithians for compound (1a), and anions of 1,3-dithians and of O-trimethylsilylcyanohydrins for compound (1b). The synthetic methods used represent new means for attaining an extensive range of acetogenins of natural origin and of biogenetic intermediates.