Hexane → cis-1-(tert-butyldimethylsilyl)-3-[(R)-1-hydroxyethyl]-4-trimethylsilylethynyl-2-azetidinone

HRID 231236Notes

Reaction equation

HRID 231236 reaction equation
[OH:1][C@@H:2]([C@H:4]1[C@@H:7]([C:8]#[C:9][Si:10]([CH3:13])([CH3:12])[CH3:11])[NH:6][C:5]1=[O:14])[CH3:3].C([Li])CCC.CCCCCC.[Si:26](Cl)([C:29]([CH3:32])([CH3:31])[CH3:30])([CH3:28])[CH3:27]>O1CCCC1.O.C(OCC)(=O)C>[Si:26]([N:6]1[C@H:7]([C:8]#[C:9][Si:10]([CH3:12])([CH3:11])[CH3:13])[C@H:4]([C@H:2]([OH:1])[CH3:3])[C:5]1=[O:14])([C:29]([CH3:32])([CH3:31])[CH3:30])([CH3:28])[CH3:27]

Participants

8

Reactant 4

HCID 8058HexaneHCID 28928tert-Butyldimethylsilyl chlorideHCID 18633014cis-3-[(R)-1-hydroxyethyl]-4-trimethylsilylethynyl-2-azetidinoneHCID 178418339Butyllithium

Product 1

HCID 67788869cis-1-(tert-butyldimethylsilyl)-3-[(R)-1-hydroxyethyl]-4-trimethylsilylethynyl-2-azetidinoneYield 32.5%

Reagents, catalysts & solvents 3

HCID 962WaterSolventHCID 8028TetrahydrofuranSolvent2×HCID 8857Ethyl AcetateSolvent

Conditions

Temperature
-70 °C

Procedure

Cis-3-[(R)-1-hydroxyethyl]-4-trimethylsilylethynyl-2-azetidinone (0.8 g) is dissolved in dry tetrahydrofuran (15 ml) in an argon stream, and the solution is cooled to -70° C. followed by dropwise addition of n-butyllithium (1.6M)-hexane (4.8 ml) while carefully maintaining the temperature so as not to exceed -65° C. To the mixture is added dropwise a solution of tert-butyldimethylsilyl chloride (0.86 g) in dry tetrahydrofuran (5 ml) at -70° C. or lower, and the resulting mixture is stirred at the same temperature for an hour and then poured into a mixture of ethyl acetate (100 ml) and water (100 ml). The organic layer is separated, washed with aqueous sodium chloride and dried over magnesium sulfate. The solvent is then distilled off under reduced pressure and the residue is subjected to silica gel column chromatography (eluent: 1:9 ethyl acetate-n-hexane mixture) to give 0.40 g of cis-1-(tert-butyldimethylsilyl)-3-[(R)-1-hydroxyethyl]-4-trimethylsilylethynyl-2-azetidinone.

Workup

  1. temperaturewhile carefully maintaining the temperature so as not
  2. customto exceed -65° C
  3. customThe organic layer is separated
  4. washwashed with aqueous sodium chloride
  5. dry with materialdried over magnesium sulfate
  6. distillationThe solvent is then distilled off under reduced pressure

Sources & evidence

ORD record
ord-b8c4ee0e9d8549ea851db02b502640f9
Source dataset
uspto-grants-1989_07
Patent number
US04845210

Reaction notes

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