Preparation of β-Cyclocitral

Abstract

An improved method for the preparation of pure β-cyclocitral by cyclization of citral anil with 95% sulfuric acid is reported. By avoidance of steam distillation of the reaction product, the formation of the by-products p-cymene and 1-acetyl-4,4-dimethyl-1-cyclohexene was prevented. The formation of this ketone by treatment of α- or β-cyclocitral anil with dilute sulfuric acid followed by steam distillation supports the mechanism proposed by Henbest et al.