Reduction of activated carbonyl groups by alkylphosphines: formation of α-hydroxy esters and ketones

Abstract

Reduction of activated carbonyl groups such as α-keto esters, benzils, 1,2-cyclohexanedione, and α-ketophosphonates by alkyl phosphines afforded the corresponding α-hydroxy esters or ketones in good to excellent yields in THF at room temperature. The mechanism of the proton transfer and intramolecular hydrolysis has been studied on the basis of deuterium and ¹⁸O labeling experiments.