PROCESS FOR PREPARATION OF OXAZOLIDINE- AND IMIDAZOLIDINE-DERIVATIVES

摘要

N-Alpha-halopropionyl-heterocyclic cpds. of formula (I) are new, where R1-R4 = H, 1-8C alkyl, aryl-(1-8C)alkyl or aryl; or R1+R2 and/or R3+R4 = 1-8C alkylene; or R1+R2+R3+R4 = residue of o-phenylene; X = halogen; Y = O or N substd. by 1-8C alkyl or aryl. Beta-lactam derivs. of formula (II) where R = H or protecting gp.. Pref. in (I) and (II), R1 = R2 = Me; R3 = R4 = H; Y = O.