Chemical Transformation of Terpenoids. VII. Syntheses of Chiral Segments, Key Building-Blocks for the Right Half of Taxane-Type Diterpenoids

Abstract

Two kinds of chiral segments, i.e. segment B-I (4) and segment B-II (5), which are potentially versatile building-blocks for construction of the right half of taxane-type diterpenoids, were synthesized from 3-methyl-2-cyclohexen-1-one (6) via optical resolution of the (2S, 3S)-2, 3-butanediol ketal derivatives (8, 15).