The formation of allyl sulphides by phenylthio-migration: control by silicon

Abstract

When γ-silyl-β-phenylthio-alcohols are treated with acid, the strategically placed silyl group encourages the rearrangement of the phenylthio-group, both from a secondary migration origin to a secondary migration terminus, and from a secondary migration origin to a tertiary migration terminus (4)→(6). Geraniol/nerol (12) and linalool (14) have been synthesised from a common intermediate (11) using this type of reaction. Phenylthio-migration from a tertiary migration origin (17)→(3) can be controlled to a limited extent by a suitably placed silyl group, but it is easier to achieve direct β-elimination of the silyl and phenylthio-groups (17)→(18).