Synthesis and absolute configuration of new chiral epoxyalcohols by stereoselective epoxidation of allylic and homoallylic alcohols with a (1R)-(+)-camphor skeleton

The chiral nonracemic alcohols 1-5 were stereoselectively epoxidized with the VO(acac)(2)/t-butyl hydroperoxide system. The epoxyalcohols 6-9 resulting from alcohols 1-4 were synthesized in high yields and the obtained diastereoisomers were isolated in pure form by chromatography. The homoallylic alcohol 5 epoxidized 100% diastereoselectively to 10. The epoxyalcohol 10 underwent a stereoselective intramolecular cyclisation during the epoxydation with rearrangement of the camphor skeleton to the oxatricyclo derivative 11. The absolute configurations of the new chiral compounds were determined by NMR methods. Copyright (C) 1996 Elsevier Science Ltd