Organophosphorus Intermediates. X. The Synthesis and Properties of the 1,4-Dioxo-2,3,4a,5,6,7,8,8a-Octahydro-1-λ-5-Phosphinoline System

Abstract

Addition of methyl 2-methoxycarbonylethylphosphinate to methyl cyclohexenoate followed by cyclization and hydrolysis affords a convenient route to the octahydrophosphinoline system. The reactions appear to be stereoselective and give predominantly the cis ring fused bicyclic compound. Stereochemistry is assigned largely on the basis of ¹³C n.m.r , spectra. Addition of methyl 2-methoxycarbonylethylphosphinate to cyclohex-2-enone and attempted cyclization of the resulting product is also reported.