| 摘要 |
The manufacture of chiral aldehydes of the general formula < IMG > in which R3 and R4 each individually represent hydrogen or lower alkyl or together represent lower alkylene, by reacting a lactone of the general formula < IMG > II in which R3 and R4 have the significance given above, with an alkali metal metaperiodate is described. The chiral aldehydes of formula I can be used for the manufacture of chiral .beta.-lactams of the general formula < IMG > III in which R1 represents a readily cleavable protecting group, R2 represents benzyloxycarbonylamino, azido, phthalimido or the group R5R6C=CR7-NH-, wherein R5 represents lower alkanoyl, lower alkoxycarbonyl or benzoyl, R6 represents hydrogen, lower alkyl, lower alkanoyl, lower alkoxycarbonyl or cyano and R7 represents hydrogen or lower alkyl, and R3 and R4 each individually represent hydrogen or lower alkyl or together represent lower alkylene. The chiral .beta.-lactams of formula III are intermediates for the manufacture of antimicrobially active .beta.-lactams. |
