Solvolysis of (4,5)-anti-4-Aryl-5-tosyloxy-2(E)-hexenoate Derivatives

Abstract

The solvolysis reaction of (4,5)-anti-4-aryl-5-tosyloxy-2(E)-hexenoates 4a—k gave (4,5)-anti-4-aryl-5-hydroxy-2(E)-hexenoates 2a—k and (4,5)-anti-5-aryl-4-hydroxy-2(E)-hexenoates 5a—k along with the complete inversion. This 1,2-aryl migration was induced by treatment with heating in water-saturated nitromethane. On the basis of the substituent effect on the aromatic ring, this 1,2-aryl migration is thought to proceed via the σ-bridged phenonium ion. The product selectivity between 2a—k and 5a—k was found to be subtly governed by the substituent and substitution pattern in the aromatic ring of the substrates 4a—k.