(4R)-4-(2'-diazo-2'-benzyloxycarbonylethylsulfonyl)-2-azetidinone → Benzyl (3S, 5R)-Penam-3-Carboxylate 1,1-Dioxide

HRID 1733202Notes

Reaction equation

HRID 1733202 reaction equation
[N+](=[C:3]([C:13]([O:15][CH2:16][C:17]1[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=1)=[O:14])[CH2:4][S:5]([C@H:8]1[NH:11][C:10](=[O:12])[CH2:9]1)(=[O:7])=[O:6])=[N-]>COCCOC.C([O-])(=O)C.C([O-])(=O)C.C([O-])(=O)C.C([O-])(=O)C.[Rh+3].[Rh+3]>[S:5]1(=[O:7])(=[O:6])[C@@H:8]2[CH2:9][C:10](=[O:12])[N:11]2[C@@H:3]([C:13]([O:15][CH2:16][C:17]2[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=2)=[O:14])[CH2:4]1

Participants

4

Reactant 1

HCID 54288551(4R)-4-(2'-diazo-2'-benzyloxycarbonylethylsulfonyl)-2-azetidinone

Product 1

HCID 131711968Benzyl (3S, 5R)-Penam-3-Carboxylate 1,1-DioxideYield 53.5%

Reagents, catalysts & solvents 2

HCID 86657289Di-rhodium tetraacetateCatalyst2×HCID 80711,2-DimethoxyethaneSolvent

Procedure

To a stirred solution of 1.80 g of (4R)-4-(2'-diazo-2'-benzyloxycarbonylethylsulfonyl)-2-azetidinone in 100 ml of 1,2-dimethoxyethane was added 3 mg of dirhodium tetraacetate. The reaction mixture was stirred for 1.5 hours and then a further 3 mg of dirhodium tetraacetate was added. Stirring was continued for 2.5 hours, and then the solvent was removed by evaporation in vacuo. The residue was dissolved in ethyl acetate, and the solution was washed twice with water at pH 8.5. The ethyl acetate solution was dried (Na2SO4) and evaporated in vacuo to give 0.88 g of product. This crude product was chromatographed on 26 g of silica gel and the product containing fractions were combined and evaporated. The residue was dissolved in boiling chloroform and then hexane was added to induce precipitation. The precipitate was recovered by filtration giving 131 mg of the title compound. The NMR spectrum (60 MHz; CDCl3) showed absorptions at 7.22 (s, 5H), 5.10 (s, 2H), 4.70 (m, 1H), 4.35 (m, 1H), 3.47 (m, 2H) and 3.32 (m, 2H) ppm. The IR spectrum (film) showed absorptions at 1800 and 1735 cm-1.

Workup

  1. stirringStirring
  2. waitwas continued for 2.5 hours
  3. customthe solvent was removed by evaporation in vacuo
  4. dissolutionThe residue was dissolved in ethyl acetate
  5. washthe solution was washed twice with water at pH 8.5
  6. dry with materialThe ethyl acetate solution was dried (Na2SO4)
  7. customevaporated in vacuo

Sources & evidence

ORD record
ord-096d9ad44ea04ee4ab0663c94cf8f803
Source dataset
uspto-grants-1980_12
Patent number
US04241050

Reaction notes

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