Photochemistry of β,γ-unsaturated oxime acetates. Aza-di-π-methane reactivity of functionalised all-aliphatic systems. A photochemical approach to pyrethrin-like cyclopropane derivatives

Abstract

The acetone-sensitized irradiation of two series of oxime acetates has been studied. The first group, oxime acetates of 4-ethoxycarbonyl-, 4-cyano-, 4-methoxymethyl- and 4-acetoxymethyl-2, 2-dimethylbut-3-enal, undergoes E-Z-isomerization of the C=C bond. The second group of compounds, oxime acetates of 4-ethoxycarbonyl-, 4-cyano-, and 4-acetoxymethyl-2,2-dimethylpent-3-enal, rearranges by the aza-di-π-methane reaction to afford cyclopropane derivatives.