SELECTIVE PREPARATION METHOD OF 3-(Z)-PROPHENYL CEPHEM COMPOUND

摘要

PURPOSE: Provided is a selective preparation method of a 3-(Z)-prophenyl cephem compound which is used as an intermediate of cefprozil, a kind of oral cephalosporin antibiotics. CONSTITUTION: The 3-(Z)-prophenyl cephem compound represented by the formula(1) is selectively manufactured by reacting a phosphoranyliden cephem compound with acetaldehyde in a mixed solvent containing ether as an essential solvent under the presence of base. In the formula, R represents a carboxy protection group; R¬1 represents hydrogen or R¬2CH2CO-; and R¬2 represents ethyl, 2-thiopen, phenyl, p-hydroxyphenyl or phenoxy.