Synthesis and reactions of 2-substituted ethyl N-alkylmalonylhydroxamic acids.

Alkylation of O-silylated N-alkylmalonylhydroxamic acids provides a method for the synthesis of 2-substituted N-alkylmalonyl hydroxamic acids. The substituent at C-2 does not materially change the chemistry of the α-lactam intermediates produced from them. They can be converted to unsymmetric ureas and hydantoins in high yields. The addition of unsaturated substituents at C-2 is used to produce cyclic ureas containing medium rings via RCM reactions.