Imidazole → Cis-3-[(R)-1-(tert-butyldimethylsilyloxy)ethyl]-4-trimethylsilylethynyl-2-azetidinone

HRID 231228Notes

Reaction equation

HRID 231228 reaction equation
[NH:1]1[CH2:4][CH2:3][C:2]1=[O:5].N1[CH:10]=[CH:9]N=C1.[Si:11](Cl)([C:14]([CH3:17])([CH3:16])[CH3:15])([CH3:13])[CH3:12].[C:19]([O:22][CH2:23][CH3:24])(=O)[CH3:20]>CN(C)C=O.O>[Si:11]([O:22][C@@H:19]([C@H:3]1[C@@H:4]([C:9]#[C:10][Si:11]([CH3:14])([CH3:13])[CH3:12])[NH:1][C:2]1=[O:5])[CH3:20])([C:14]([CH3:17])([CH3:16])[CH3:15])([CH3:13])[CH3:12].[Si:11]([O:22][CH:23]([C@H:3]1[C@H:4]([C:9]#[C:10][Si:11]([CH3:14])([CH3:13])[CH3:12])[NH:1][C:2]1=[O:5])[CH3:24])([C:14]([CH3:17])([CH3:16])[CH3:15])([CH3:13])[CH3:12]

Participants

8

Reactant 4

HCID 795ImidazoleHCID 8857Ethyl AcetateHCID 28928tert-Butyldimethylsilyl chlorideHCID 1367212-Azetidinone

Product 2

HCID 57192380Cis-3-[(R)-1-(tert-butyldimethylsilyloxy)ethyl]-4-trimethylsilylethynyl-2-azetidinoneHCID 67788757trans-3-[1-(Tert-butyldimethylsilyloxy)ethyl]-4-trimethylsilylethynyl-2-azetidinone

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 6228DimethylformamideSolvent

Conditions

Temperature
60 °C

Procedure

A cis/trans mixture (1.44 g) of 3-(1-hydroxyethyl)-4-trimethylsilylethynyl)-2-azetidinone is dissolved in N,N-dimethylformamide (15 ml), and imidazole (1.4 g) and tert-butyldimethylsilyl chloride (3.0 g) are added. The mixture is stirred at 60° C. for 2 hours and then poured into a mixture of ethyl acetate (100 ml) and water (50 ml). The organic layer is separated, serially washed with water and aqueous sodium chloride, dried over magnesium sulfate and concentrated under reduced pressure. The residue is subjected to silica gel column chromatography to give 0.62 g of cis-3-[(R)-1-(tert-butyldimethylsilyloxy)ethyl]-4-trimethylsilylethynyl-2-azetidinone, 0.97 g of trans-3-[1-(tert-butyldimethylsilyloxy)ethyl]-4-trimethylsilylethynyl-2-azetidinone and 0.36 g of a cis/trans mixture. The physical characteristics of the cis form are identical with those of the compound obtained in Example 4. Physical characteristics of the trans compound

Workup

  1. customThe organic layer is separated
  2. washserially washed with water and aqueous sodium chloride
  3. dry with materialdried over magnesium sulfate
  4. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-425934b43c0149d2a04a1fff09b4eec1
Source dataset
uspto-grants-1989_07
Patent number
US04845210

Reaction notes

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