Sodium Hydroxide → (3S,4S)-3-[(1R)-1-t-butyldimethylsilyloxyethyl]-4-[(1R)-1-benzyloxycarbonylethyl]-1-(t-butyloxycarbonylmethyl)azetidin-2-one

HRID 21705Notes

Reaction equation

HRID 21705 reaction equation
[Si:1]([O:8][C@@H:9]([C@@H:11]1[C@@H:14]([C@H:15]([C:17]([O:19][CH2:20][C:21]2[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]=2)=[O:18])[CH3:16])[NH:13][C:12]1=[O:27])[CH3:10])([C:4]([CH3:7])([CH3:6])[CH3:5])([CH3:3])[CH3:2].Br[CH2:29][C:30]([O:32][C:33]([CH3:36])([CH3:35])[CH3:34])=[O:31].[OH-].[Na+]>C(Cl)Cl.[Cl-].C([N+](CC)(CC)CC1C=CC=CC=1)C.O.C(OCC)C>[Si:1]([O:8][C@@H:9]([C@@H:11]1[C@@H:14]([C@H:15]([C:17]([O:19][CH2:20][C:21]2[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]=2)=[O:18])[CH3:16])[N:13]([CH2:29][C:30]([O:32][C:33]([CH3:36])([CH3:35])[CH3:34])=[O:31])[C:12]1=[O:27])[CH3:10])([C:4]([CH3:5])([CH3:6])[CH3:7])([CH3:3])[CH3:2]

Participants

8

Reactant 3

HCID 14798Sodium HydroxideHCID 79177tert-Butyl bromoacetateHCID 11784145(3S,4S)-3-[(1R)-1-t-butyldimethylsilyloxyethyl]-4-[(1R)-1-benzyloxycarbonylethyl]azetidin-2-one

Product 1

HCID 10255617(3S,4S)-3-[(1R)-1-t-butyldimethylsilyloxyethyl]-4-[(1R)-1-benzyloxycarbonylethyl]-1-(t-butyloxycarbonylmethyl)azetidin-2-one

Reagents, catalysts & solvents 4

HCID 66133Benzyl triethylammonium chlorideCatalystHCID 962WaterSolventHCID 3283Diethyl EtherSolventHCID 6344DichloromethaneSolvent

Procedure

To a solution of (3S,4S)-3-[(1R)-1-t-butyldimethylsilyloxyethyl]-4-[(1R)-1-benzyloxycarbonylethyl]azetidin-2-one (755 mg) in methylene chloride (10 ml), there were added successively t-butyl bromoacetate (1.88 g), 50% sodium hydroxide (620 mg) and triethylbenzylammonium chloride (220 mg), followed by stirring at room temperature for 2 hours. The reaction mixture was diluted with water and diethyl ether. The aqueous layer was separated from the organic layer and extracted two times with diethyl ether. The extracts were combined with the organic layer, washed with water two times and brine three times, dried over sodium sulfate and evaporated. The residue was purified by silica gel chromatography to give (3S,4S)-3-[(1R)-1-t-butyl-dimethylsilyloxyethyl]-4-[(1R)-1-benzyloxycarbonylethyl]-1-(t-butyloxycarbonylmethyl)azetidin-2-one.

Workup

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

Sources & evidence

ORD record
ord-0f6e3777bde741558959619c88c4fe04
Source dataset
uspto-grants-1995_06
Patent number
US05424422

Reaction notes

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