2,2′,4,4′,6-Penta-tert-butylbenzil: an unexpected product in the attempted coupling of tri-tert-butylbenzoyl chloride with magnesium–magnesium iodide

Abstract

Reduction of 2,4,6-tri-tert-butylbenzoyl chloride with Mg–MgI₂ in 1∶1 diethyl ether–benzene under ultrasonic irradiation gives the hexa-tert-butyl-benzil and -benzoin and also 2,2′,4,4′,6-penta-tert-butylbenzil. Possible mechanisms for the loss of the Bu^t group are discussed.