تفاعل #54385

معادلة التفاعل

ozone oxygen

2-[4-(p-toluenesulphonylthio)-3-(α-tert.butoxycarbonylamino-α-phenylacetylamino)-2-oxoazetidin-1-yl]-3-methylene-butyric acid diphenylmethyl ester

dimethyl sulphide

→

2-[4-(p-toluenesulphonylthio)-3-(α-tert.butoxycarbonylamino-α-phenylacetylamino)-2-oxoazetidin-1-yl]-3-hydroxy-crotonic acid diphenylmethyl ester

المذيبات

methylene chloride

ظروف التفاعل

المعالجة

1. 1
   درجة الحرارةwithout cooling
2. 2
   تركيزis then concentrated by evaporation in vacuo
3. 3
   أخرىThe residue is recrystallised from methylene chloride/ether/hexane

الإجراء التجريبي

An ozone/oxygen stream (0.5 mmol per minute) is passed for 7 minutes into a solution, cooled to -70° C., of 2.30 g (3.0 mmols) of 2-[4-(p-toluenesulphonylthio)-3-(α-tert.butoxycarbonylamino-α-phenylacetylamino)-2-oxoazetidin-1-yl]-3-methylene-butyric acid diphenylmethyl ester in 230 ml of methylene chloride. After adding 1 ml of dimethyl sulphide, the solution is stirred for a further hour without cooling and is then concentrated by evaporation in vacuo. The residue is recrystallised from methylene chloride/ether/hexane and gives 2-[4-(p-toluenesulphonylthio)-3-(α-tert.butoxycarbonylamino-α-phenylacetylamino)-2-oxoazetidin-1-yl]-3-hydroxy-crotonic acid diphenylmethyl ester of melting point 182°-184° C.; UV spectrum (ethanol): ~max = 259 mμ (ε =13,400); IR spectrum (methylene chloride): characteristic bands at 2.92, 5.59, 5.83, 5.92, 6.03 (shoulder), 6.18 and 6.68 μ; thin layer chromatogram: Rf value~ 0.55 (silica gel; toluene/ethyl acetate, 1:1).

المصدر