Stereochemical Studies. XXVI. Asymmetric Synthesis using Proline Derivatives of optically Active Various 4, 4-Disubstituted 2-Cyclohexenones with Enamine Alkylation

Abstract

Enamines III, prepared from some disubstituted acetaldehydes I and L-proline pyrrolidide (II), were alkylated with methyl vinyl ketone to generally afford optically active 4, 4-disubstituted 2-cyclohexenones V. This asymmetric synthesis is found to be widely applicable, their absolute configurations could be deduced by a comparison of the two substituents.