Reactions of allylic quaternary ammonium salts with alcohols in the synthesis of terpene ethers

Abstract

Reactions of quaternary ammonium salts bearing 2,7-dimethylocta-2,7-dien-1-yl moiety with primary alcohols (isoamyl and crotyl alcohols and geraniol) can be directed mainly to the allylic position to afford the corresponding ethers with the displacement of the ammonium leaving group. The reaction took place in the presence of NaOH under solvent-free conditions upon reflux or at heating at 150 °C. An important factor of regio-selectivity is a high steric hindrance of such ammonium group leaving group as R₂(Allyl)N⁺. In the case of the derivative with Et₂MeN⁺ group, alcohols attack the alkyl substituent.