Intramolecular Participation Reactions in Labda-8(17),14-dien-13-ol (Manool) Derivatives

Abstract

Lewis acid treatment of a series of hydroxy epoxides promoted intramolecular nucleophilic epoxide opening to give hydroxy cyclic ethers. The regioselectivity of epoxide opening is controlled by a preference for S_N2 attack at the more accessible epoxide carbon, provided this does not involve the formation of a strained ether ring. An intramolecular acetate transfer occurs in order to achieve the regioselective opening.