To obtain the subject compound useful as pharmaceuticals in high purity and yield by reacting a halogenated β-lactam with a specific reagent in the presence of a specific metal compound.
This 3-norcephem compound of formula II can be produced by reacting a compound of formula I [R1 is H, amino or a protected amino; R2 is a (substituted) aryl; (n) is 0-2; R3 is H or a carboxylic acid protecting group; X is a halogen; Y is a halogen or an eliminable group] with a hydride reagent (e.g. tributyltin hydride) in the presence of a cuprous compound (e.g. cuprous chloride) at -10 to +80°C optionally in an inert gas atmosphere. The amounts of the hydride reagent and the cuprous compound are 1-30 times mol and 1-30 equivalent based on the compound of formula I, respectively. The objective compound can easily be produced in one step using the compound of formula I easily derived from penicillin as the starting raw material in place of the use of a cephem compound difficult to synthesize and proceeding the cyclization reaction simultaneously with reduction.
TORII SHIGERU
TANAKA HIDEO
KIKUCHI AKIRA
KAMEYAMA YUTAKA
