| abstract |
A process for preparing azetidinone derivatives represented by the general formula (I), wherein R 1 represents straight-chain or branched lower alkyl, substituted or unsubstituted aryl, substituted or unsubstituted phenylmethyl, or substituted or unsubstituted phenyloxymethyl, R 2 represents hydrogen, optionally substituted hydrocarbyl or an amino-protecting group selected from among acyl, silyl, sulfonyl, and phosphonyl, R 3 represents a substituted or unsubstituted aryl group or a substituted or unsubstituted heterocylic group. |