Resolution of 2,3-dihydrosqualene-2,3-diol, 10,11-dihydro-10,11-dihydroxyfarnesyl benzoate, and 6,7-dihydro-6,7-dihydroxygeranyl benzoate. Synthesis of (3R)- and (3S)-2,3-epoxy-2,3-dihydrosqualene

Abstract

The title compounds are conveniently resolved by reaction with 3β-acetoxy-17β-chloroformylandrost-5-ene and chromatographic separation of the resulting diastereoisomeric esters. The absolute configurations of the enantiomers have been established. The important biosynthetic precursors, (+)-(3R)- and (–)-(3S)-2,3-epoxy-2,3-dihydrosqualene are readily prepared from (–)-(3S)- and (+)-(3R)-2,3-dihydrosqualene-2,3-diol by treatment with toluene-p-sulphonyl chloride in pyridine, followed by base.