Lengthening the chain of a dicarboxylic acid by one carbon atom
Abstract
The normal five-step procedure for the process indicated in the title has been shortened to three steps by using the reaction between diazomethane and a cyclic anhydride to prepare the intermediate diazo-ketone ester. This is illustrated by the synthesis of methyl 2-(1-benzyl-5-methoxycarbonylpyrrolidin-2-yl)acetate from 1-benzylpyrrolidine-2,5-dicarboxylic anhydride.