Dimethyl Sulfoxide → (3S,4S)-3-acetyl-1-(tert-butyldimethylsilyl)-4-trimethylsilylethynyl-2-azetidinone

HRID 231237Notes

Reaction equation

HRID 231237 reaction equation
FC(F)(F)C(O)=O.CS(C)=O.[Si:12]([N:19]1[C@H:22]([C:23]#[C:24][Si:25]([CH3:28])([CH3:27])[CH3:26])[C@H:21]([C@H:29]([OH:31])[CH3:30])[C:20]1=[O:32])([C:15]([CH3:18])([CH3:17])[CH3:16])([CH3:14])[CH3:13].C(N(CC)CC)C>C(Cl)Cl.O.C(OCC)(=O)C>[C:29]([C@@H:21]1[C@@H:22]([C:23]#[C:24][Si:25]([CH3:27])([CH3:26])[CH3:28])[N:19]([Si:12]([C:15]([CH3:18])([CH3:17])[CH3:16])([CH3:14])[CH3:13])[C:20]1=[O:32])(=[O:31])[CH3:30]

Participants

8

Reactant 4

HCID 679Dimethyl SulfoxideHCID 6422Trifluoroacetic acidHCID 8471TriethylamineHCID 67788869cis-1-(tert-butyldimethylsilyl)-3-[(R)-1-hydroxyethyl]-4-trimethylsilylethynyl-2-azetidinone

Product 1

HCID 53923801(3S,4S)-3-acetyl-1-(tert-butyldimethylsilyl)-4-trimethylsilylethynyl-2-azetidinoneYield 32.7%

Reagents, catalysts & solvents 3

HCID 962WaterSolventHCID 6344DichloromethaneSolvent3×HCID 8857Ethyl AcetateSolvent

Conditions

Temperature
-70 °C

Procedure

In an argon stream, a solution of dry trifluoroacetic acid (0.2 ml) in methylene chloride (3 ml) is added dropwise to a mixture of dimethyl sulfoxide (0.1 ml) and methylene chloride (10 ml) at -65° C. or lower, and the mixture is stirred at -70° C. for 0.5 hours. A solution of cis-1-(tert-butyldimethylsilyl)-3-[(R)-1-hydroxyethyl]-4-trimethylsilylethynyl-2-azetidinone (0.4 g) in methylene chloride (4 ml) is added dropwise at -65° C. or lower and the mixture is stirred at the same temperature for 0.5 hour. After addition of triethylamine (0.3 ml) at the same temperature, the temperature is gradually raised to room temperature. The reaction mixture is poured into a mixture of ethyl acetate (70 ml) and water (100 ml), and the organic layer is separated, washed with aqueous sodium chloride, dried over magnesium sulfate and concentrated under reduced pressure. The residue is subjected to silica gel column chromatography (eluent: 3% ethyl acetate-97% n-hexane) to give trans i.e. (3S,4S)-3-acetyl-1-(tert-butyldimethylsilyl)-4-trimethylsilylethynyl-2-azetidinone (0.13 g)

Workup

  1. stirringlower and the mixture is stirred at the same temperature for 0.5 hour
  2. temperaturethe temperature is gradually raised to room temperature
  3. customthe organic layer is separated
  4. washwashed with aqueous sodium chloride
  5. dry with materialdried over magnesium sulfate
  6. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-bbcc503110d94085a8f8865eb0323174
Source dataset
uspto-grants-1989_07
Patent number
US04845210

Reaction notes

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