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Syntheses of 4 novel chiral azetidin 2 one derivatives, which were characterized by 1H NMR, IR, specific rotation and elemental analysis, through Staudinger cycloaddition reaction of Schiff base of benzaldehyde with chlorine substitution at different position in benzene ring, were described. For the first time, this type of 3 S ,4 R configuration azetidin 2 one mono~crystals with many chiral centers [(3 S ,4 R ) 3 hydroxy N [( S ) (1 phenyl)ethyl ] 4 (2′ chlorophenyl) azetidin 2 one mono~crystal] were obtained, the structures of which were determined by X ray dif fraction analysis. The effects of Schiff base of benzaldehyde with chlorine subs titu tion at different position in benzene ring on stereoselectivity of Staudinger cy cloaddition reaction products were discussed and the results are showed as below : 2 chlorophenyl Schiff base favored to yield 3 S ,4 R configuration prod uct, but 4 chlorophenyl Schiff base favored to yield 3 R ,4 S configuration produc t. The re action orientation of 2,4 dichlorophenyl Schiff base was determined by corporat e effect of 2 and 4 chlorine, and that of the 4 chlorine was more obvious. In co ntrast to 4 chlorophenyl, although the main product was 3 R ,4 S configur ation, 3 chlorophenyl owned lower selectivity.
Syntheses of 4 novel chiral azetidin 2 one derivatives, which were characterized by 1H NMR, IR, specific rotation and elemental analysis, through Staudinger cycloaddition reaction of Schiff base of benzaldehyde with chlorine substitution at different position in benzene ring, were described. For the first This type of 3 S, 4 R configuration azetidin 2 one mono ~ crystals with many chiral centers [(3 S, 4 R) 3 hydroxy N [(S) (1 phenyl) ethyl] 4 the structures of which were determined by X ray dif fraction analysis. The effects of Schiff base of benzaldehyde with chlorine subsituation at different position in benzene ring on stereoselectivity of Staudinger cy cloaddition reaction products were discussed and the results are showed as below: 2 chlorophenyl Schiff base favored to yield 3 S, 4 R configuration prod uct, but 4 chlorophenyl Schiff base favo Red to yield 3 R, 4 S configuration produc t. The re action orientation of 2,4 dichlorophenyl Schiff base was determined by corporat e effect of 2 and 4 chlorine, and that of the 4 chlorine was more obvious. In co ntrast to 4 chlorophenyl, although the main product was 3 R, 4 S configur ation, 3 chlorophenyl owned lower selectivity.