| abstract |
NEW MATERIAL:The optically active 2-azetidinone derivative of formula I [R is lower alkyl, (substituted) aryl or (substituted) aralkyl]. n EXAMPLE: (4R)-4-Phenylthioazetidin-2-one. n USE: Useful as a synthetic intermediate of an antibiotic substance containing β-lactam ring, e.g. a carbapenem antibiotics such as thienamycin, etc. or monocyclic β-lactam antibiotic, etc. n PROCESS: The compound of formula I can be prepared by reacting the compound of formula II [X is lower alkanoyloxy or (substituted) arylsulfonyl] with the compound of formula III in the presence of cinchonidien in a solvent such as diethyl ether, etc. The amount of cinchonidine is 0.5W3mol, preferably 1W2mol per 1mol of the compound of formula II, and that of the compound of formula IIIis about 1W8mol per 1mol of the compound of formula II. n COPYRIGHT: (C)1984,JPO&Japio |