| abstract |
A process for preparing an azetidinone of the formula: <IMAGE> which comprises reacting a C-unsubstituted methyleneamine of the formula: <IMAGE> with R2-CH2COOH, its acid halide or anhydride, in the presence of boron trihalide and an organic base, wherein R1 is an organic residue bearing a carboxy group or its derivative and R2 is azido, substituted amino, halogen, acyloxy, alkoxy, aryloxy or aralkoxy. |