Stereoselective synthesis of allyl- and homoallylglycines

A new method for the synthesis of N-protected allyl- and homoallylglycines was developed from aspartic and glutamic acid derivatives. The carboxylic side-chains of aspartic and glutamic derivatives was first transformed into the Weinreb amide by coupling with N,O-dimethylhydroxylamine and then reduced into the corresponding aldehyde. The latter could react with methyl-triphenylphosphonium bromide to yield the title compounds with 50% total yield.