Reactions of aryl glyoxylic esters with trivalent phosphorus compounds; the preparation of αβ-dimethoxycarbonylstilbene oxides

Abstract

A number of substituted αβ-dimethoxycarbonylstilbene oxides has been prepared by reductive condensation of the corresponding methyl phenylglyoxylates with hexamethylphosphorous triamide; these oxirans undergo [3 → 2 + 1] photocycloelimination to give aryl methoxycarbonylcarbenes and exhibit photochromic behaviour at 77K in rigid matrices, indicative of carbonyl ylide formation.