반응 #54378

반응 방정식

ozone

2-[4-(benzthiazol-2-yldithio)-3-phenoxyacetamido-2-oxoazetidin-1-yl]-3-methylene-butyric acid diphenylmethyl ester

→

2-[4-(Benzthiazol-2-yldithio)-3-phenoxyacetamido-2-oxoazetidin- 1-yl]-3-hydroxy-crotonic acid diphenylmethyl ester

용매

ethyl acetate

반응 조건

후처리

1. 1
   온도to warm up
2. 2
   농축concentrated to 10 ml in vacuo
3. 3
   workup.ADDITIONmixed with 1.0 ml of dimethyl sulphide
4. 4
   기타Solvent and excess reagent are removed in vacuo
5. 5
   기타the residue is chromatographed on 30 g of acid-washed silica gel

실험 절차

1 equivalent of ozone (diluted with oxygen) is passed into a solution, cooled to -70° C., of 681 mg (1.0 mM) of 2-[4-(benzthiazol-2-yldithio)-3-phenoxyacetamido-2-oxoazetidin-1-yl]-3-methylene-butyric acid diphenylmethyl ester in 30 ml of ethyl acetate. The reaction solution is allowed to warm up, concentrated to 10 ml in vacuo, mixed with 1.0 ml of dimethyl sulphide and stirred for 15 hours at room temperature. Solvent and excess reagent are removed in vacuo and the residue is chromatographed on 30 g of acid-washed silica gel, using toluene/ethyl acetate, 4:1 (15 ml fractions). 2-[4-(Benzthiazol-2-yldithio)-3-phenoxyacetamido-2-oxoazetidin- 1-yl]-3-hydroxy-crotonic acid diphenylmethyl ester is obtained as a solid amorphous substance. [α]D = 130° ± 1° (CHCl3 ; c= 0.8) IR spectrum (CH2Cl2): 2.95, 5.60, 5.92, 6.04 and 8.10 μ.

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