Aqueous Solvents Dictate the Regiochemistry in the Photooxidations of α,β-Unsaturated Carboxylic Acid Salts

Abstract

Aqueous singlet oxygen photooxidations of the sodium salts of angelic acid, tiglic acid, and 2,3-dimethyl-2-butenoic acid were conducted. Each reaction produced an overwhelming amount of the ene hydroperoxide resulting from hydrogen abstraction geminal to the electron withdrawing group. The resulting regiochemistry is insensitive to the alkyl substitution on the substrate.