Regiospecificity in reactions of metal phenoxides. Synthesis of 2,2′-alkylidenebisphenols

Abstract

The reactions between aryloxymagnesium bromides (1) with linear aliphatic aldehydes (2) and their acetals (10) in aprotic solvents of variable donicity have been investigated. In benzene high ortho-regiospecificity is observed in all cases, although with the aldehyde (2) the yield of 2,2′-alkylidenebisphenols (5) is usually low because of the competing aldehyde self-condensation. This process is avoided using diethyl acetals as electrophilic reagents which give the products (5) in good yields.