The Wittig reaction with glutaric and succinic anhydrides

Abstract

Six-membered cyclic anhydrides, including glutaric and some of its alkylated derivatives, have been shown to yield enol-lactones with ethoxycarbonylmethylenetriphenylphosphorane; the (E)isomer is formed preferentially. The reactions of methyl-substituted succinic anhydrides with the same phosphorane give predominantly the (E) enol-lactone in all examples. The influence of alkyl substitutents on the rates of the reactions and the product ratios in both the succinic and glutaric anhydride series is discussed.