反应详情

To a solution of oxalyl chloride (8.5 ml) in dry dichloromethane (212 ml) was added dropwise a mixture of dimethylsulfoxide (14.5 ml) and dichloromethane (42.5 ml) at -50° C., and the resultant mixture was stirred for 10 minutes at the same temperature as above. A solution of (3S,4S)-4-(1-hydroxymethylethenyl)-3-(1-(R)-benzyloxycarbonyloxyethyl)-1-di(p-anisyl)methyl-2-azetidinone (45 g) in dry dichloromethane (400 ml) was added dropwise thereto at -50° C. or less over a period of 15 minutes, followed by stirring for 15 minutes. Triethylamine (64 ml) was then dropwise added thereto, and the reaction mixture was warmed to room temperature, diluted with cold water (480 ml) and acidified with 6N hydrochloric acid (65 ml). The organic layer was washed successively with brine (200 ml×3), 2% sodium bicarbonate (200 ml) and then brine (200 ml) and dried over anhydrous sodium sulfate. Filtration and concentration of the, filtrate in vacuo gave (3S,4S)-4-(1-formylethenyl)-3-(1-(R)-benzyloxycarbonyloxyethyl)-1-di(p-anisyl)methyl-2-azetidinone.

1. washThe organic layer was washed successively with brine (200 ml×3), 2% sodium bicarbonate (200 ml)
2. dry with materialbrine (200 ml) and dried over anhydrous sodium sulfate
3. filtrationFiltration and concentration of the, filtrate in vacuo