Synthesis and reactions of some optically active epoxides formally derived from tertiary allylic alcohols

Abstract

The epoxyketones 2, 3 and 7–9 reacted with Grignard reagents in a highly stereocontrolled manner to give the epoxyalcohols 20, 4–6 and 11-13 in high yields. The epoxyalcohol 12 underwent a Payne rearrangement on base treatment to give the isomer 15 while epoxyalcohols 4, 5, 12 and 20 suffered ring-opening (with retention of configuration) using tin(IV) chloride to afford chlorodiols 18, 17, 19 and 21 respectively. On the other hand, the alcohols 4, 5 and 12 reacted with trialkylsilyl chlorides to furnish the chlorodiols 22, 24 and 23 respectively with inversion of configuration.