Trimethylsilyl triflate → (3S,4R)-4-[2-(1-allyloxycarbonylpyrrolidin-3-yl)-2-oxoethyl]-3-[(1R)-1-t-butyldimethylsilyloxyethyl]-2-oxoazetidine

HRID 1029607Notes

Reaction equation

HRID 1029607 reaction equation
C(O[C@H:5]1[NH:8][C:7](=[O:9])[C@@H:6]1[C@H:10]([O:12][Si:13]([C:16]([CH3:19])([CH3:18])[CH3:17])([CH3:15])[CH3:14])[CH3:11])(=O)C.FC(F)(F)S(O[Si](C)(C)C)(=O)=O.[C:32]([CH:35]1[CH2:39][N:38]([C:40]([O:42][CH2:43][CH:44]=[CH2:45])=[O:41])[CH2:37][CH2:36]1)(=[O:34])[CH3:33].C(=O)([O-])O.[Na+]>ClCCl.O.C(OCC)(=O)C.C(N(CC)CC)C>[CH2:43]([O:42][C:40]([N:38]1[CH2:37][CH2:36][CH:35]([C:32](=[O:34])[CH2:33][C@H:5]2[NH:8][C:7](=[O:9])[C@@H:6]2[C@H:10]([O:12][Si:13]([C:16]([CH3:17])([CH3:18])[CH3:19])([CH3:14])[CH3:15])[CH3:11])[CH2:39]1)=[O:41])[CH:44]=[CH2:45]

Participants

9

Reactant 4

HCID 65367Trimethylsilyl triflate2×HCID 516892Sodium BicarbonateHCID 10935078AzetidonHCID 151171953-Acetyl-1-allyloxycarbonylpyrrolidine

Product 1

HCID 15117203(3S,4R)-4-[2-(1-allyloxycarbonylpyrrolidin-3-yl)-2-oxoethyl]-3-[(1R)-1-t-butyldimethylsilyloxyethyl]-2-oxoazetidineYield 55.7%

Reagents, catalysts & solvents 4

HCID 962WaterSolventHCID 6344DichloromethaneSolvent2×HCID 8471TriethylamineSolvent2×HCID 8857Ethyl AcetateSolvent

Conditions

Temperature
0 °C

Procedure

To a solution of (3R,4R)-4-acetoxy-3-[(1R)-1-t-butyldimethylsilyloxyethyl]-2-oxoazetidine (2.2 g) and triethylamine (1.1 ml) in dichloromethane (20 ml) was added trimethylsilyl trifluoromethanesulfonate (1.5 ml) at -60° C. under nitrogen, and the mixture was stirred at 0° C. for 30 minutes (Solution A). To a solution of 4-acetyl-1-allyloxycarbonylpyrrolidine (1.0 g) and triethylamine (0.71 ml) in dichloromethane (10 ml) was added trimethylsilyl trifluoromethanesulfonate (0.98 ml) at -60° C. under nitrogen and the resulting mixture was stirred at 0° C. for 30 minutes. To this mixture was added dropwise the Solution A at 0° C. under nitrogen, and the mixture was stirred for additional 4 hours at 0° C. The reaction mixture was taken up into a mixture of ethyl acetate and water and the mixture was stirred at ambient temperature for 2 hours. After adjusting pH to around 6.5 with aqueous sodium hydrogen carbonate, the organic layer was separated, washed with brine, dried over magnesium sulfate and evaporated in vacuo. The residue was chromatographed on silica gel eluting with a mixture of n-hexane and ethyl acetate (1:2, V/V) to give (3S,4R)-4-[2-(1-allyloxycarbonylpyrrolidin-3-yl)-2-oxoethyl]-3-[(1R)-1-t-butyldimethylsilyloxyethyl]-2-oxoazetidine (1.2 g).

Workup

  1. stirringthe mixture was stirred for additional 4 hours at 0° C
  2. stirringthe mixture was stirred at ambient temperature for 2 hours
  3. customthe organic layer was separated
  4. washwashed with brine
  5. dry with materialdried over magnesium sulfate
  6. customevaporated in vacuo
  7. customThe residue was chromatographed on silica gel eluting with a mixture of n-hexane and ethyl acetate (1:2, V/V)

Sources & evidence

ORD record
ord-d0596760c065400d8034f3db503bac08
Source dataset
uspto-grants-1992_04
Patent number
US05102877

Reaction notes

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