γγ-Disubstituted itaconic acids. Part V. Stobbe condensation of phenyl, p-anisyl, and p-chlorophenyl isopropyl ketones with diethyl succinate

Abstract

Phenyl, p-anisyl, and p-chlorophenyl isopropyl ketones condense with diethyl succinate in the presence of potassium t-butoxide to give predominantly the cis-4-aryl-3-ethoxycarbonyl-5-methylhex-3-enoic acids in the first two cases, and the corresponding trans-4-aryl compound in the last. The half esters are further converted into naphthalene or indenone derivatives according to their configuration. An interpretation of the relative proportions of stereoisomers produced in terms of polar factors is given.