THE INTERACTION OF ALKYL ALPHA-(S)-MALATES WITH N,N'-DICYCLOHEXYLCARBOMIIDE UNDER MILD CONDITIONS

The autopolycondensation of alkyl alpha-(S)-malates in the presence of N,N'-dicyclohexylcarbodiimide under mild conditions was studied. It was established that the final product consists of low molecular N-acyl derivatives and optically active polyester fraction with MBAR(n) up to 4000 and low polydispersity MBAR(w)/MBAR(n) = 1.1 divided by 1.5. When malic acid was used as a monomer surprisingly low molecular weight products of ester and anhydride nature were obtained instead of the expected polymalic network. All the polymer fractions separated were optically active oligoesters which could be used as biodegradable carriers of pharmaceutical agents.