Structure odour studies with some diterpene derived acetals

Abstract

Acetals (1) and (2), analogous to the valued perfumery acetals (3) and (4), have been synthesized from manool (5) for structure/odour comparison. Selenoxide elimination gave diene (13) which underwent Cope rearrangement and selective epoxidation to give the 8β,9β-epoxide (19). Borontrifluoride-catalysed rearrangement established this stereochemistry and led by selective oxymercuration of diene (24) to the required acetals.