Phosphoric Acid → (3S,4S)-3-[(1R)-1-t-butyldimethylsilyloxyethyl]-4-[(1R)-1-phenylthiocarbonylethyl]-1-(t-butyloxycarbonylmethyl)azetidin-2-one

HRID 21707Notes

Reaction equation

HRID 21707 reaction equation
[H-].[Na+].Br[CH2:4][C:5]([O:7][C:8]([CH3:11])([CH3:10])[CH3:9])=[O:6].[Si:12]([O:19][C@@H:20]([C@@H:22]1[C@@H:25]([C@H:26]([C:28]([C:30]2[CH:35]=[CH:34][CH:33]=[CH:32][CH:31]=2)=[S:29])[CH3:27])[NH:24][C:23]1=[O:36])[CH3:21])([C:15]([CH3:18])([CH3:17])[CH3:16])([CH3:14])[CH3:13].P(=O)(O)(O)O>CN(C)C=O.C(OCC)C>[Si:12]([O:19][C@@H:20]([C@@H:22]1[C@@H:25]([C@H:26]([C:28]([C:30]2[CH:31]=[CH:32][CH:33]=[CH:34][CH:35]=2)=[S:29])[CH3:27])[N:24]([CH2:4][C:5]([O:7][C:8]([CH3:11])([CH3:10])[CH3:9])=[O:6])[C:23]1=[O:36])[CH3:21])([C:15]([CH3:16])([CH3:17])[CH3:18])([CH3:14])[CH3:13]

Participants

7

Reactant 4

HCID 1004Phosphoric AcidHCID 24758Sodium hydrideHCID 79177tert-Butyl bromoacetateHCID 57298084HCID 57298084, compound

Product 1

HCID 57167548(3S,4S)-3-[(1R)-1-t-butyldimethylsilyloxyethyl]-4-[(1R)-1-phenylthiocarbonylethyl]-1-(t-butyloxycarbonylmethyl)azetidin-2-one

Reagents, catalysts & solvents 2

HCID 3283Diethyl EtherSolventHCID 6228DimethylformamideSolvent

Procedure

To a suspension of sodium hydride (31 mg) in dry dimethylformamide (4.3 ml), there were added successively t-butyl alpha-bromoacetate (835 mg) and (3S,4S)-3-[(1R)-1-t-butyldimethylsilyloxyethyl]-4-[(1R)-1-phenylthiocarbonylethyl]azetidin-2-one (0.42 g), and the resultant mixture was stirred at room temperature for 1 hour under a nitrogen stream. The reaction mixture was diluted with diethyl ether and adjusted to pH 6.86 with a phosphoric acid buffer solution. The aqueous layer was separated from the organic layer and extracted with diethyl ether three times. The extracts were combined with the organic layer, washed three times with brine, dried over sodium sulfate and evaporated. The residue was purified by silica gel chromatography to give (3S,4S)-3-[(1R)-1-t-butyldimethylsilyloxyethyl]-4[(1R)-1-phenylthiocarbonylethyl]-1-(t-butyloxycarbonylmethyl)azetidin-2-one.

Workup

  1. customThe aqueous layer was separated from the organic layer
  2. extractionextracted with diethyl ether three times
  3. washwashed three times with brine
  4. dry with materialdried over sodium sulfate
  5. customevaporated
  6. customThe residue was purified by silica gel chromatography

Sources & evidence

ORD record
ord-491c0c3e8ed74057b5398d124b92cbeb
Source dataset
uspto-grants-1995_06
Patent number
US05424422

Reaction notes

Loading…