| Abstract: | The synthesis of polymers containing O-tert-butyl-L -serine, O-tert-butyl-DL -serine, L -serine, and DL -serine is reported. The N-benzyloxycarbonyl-(L or DL )-serine benzyl ester was used to synthesize the corresponding N-benzyloxycarbonyl-O-tert-butyl-(L or DL )-serine benzyl ester. Catalytic hydrogenation of this material gave O-tert-butyl-(L or DL )-serine. The reaction of O-tert-butyl-(L or DL )-serine with phosgene produced the corresponding N-carboxyanhydrides. The kinetics of polymerization of N-carboxyanhydrides were investigated to facilitate, the preparation of block copolymers. The O-tert-butyl blocking group was removed from polymers by treatment with HCl and HBr in benzene. Both high molecular weight (water-insoluble) and low molecular weight (water-soluble) homopolymers have been prepared, as well as water-soluble block copolymers of the type (DL -serine)x (L -serine)y, (DL -serine)z. |
