Acetoin → (2RS,3SR)-2-(3-benzyloxy-5-fluorophenyl)-3-(tert-butyldimethylsilyloxy)butan-2-ol

HRID 249377

Reaction equation

HRID 249377 reaction equation
[Si:1]([O:8][CH:9]([CH3:13])[C:10](=[O:12])[CH3:11])([C:4]([CH3:7])([CH3:6])[CH3:5])([CH3:3])[CH3:2].OC(C)C(=O)C.[Si](Cl)(C(C)(C)C)(C)C.N1C=CN=C1.[CH2:33]([O:40][C:41]1[CH:42]=[C:43]([Mg]Br)[CH:44]=[C:45]([F:47])[CH:46]=1)[C:34]1[CH:39]=[CH:38][CH:37]=[CH:36][CH:35]=1.BrC1C=C(OCC2C=CC=CC=2)C=C(F)C=1.[Mg]>C(OCC)C.O1CCCC1>[CH2:33]([O:40][C:41]1[CH:42]=[C:43]([C:10]([OH:12])([CH:9]([O:8][Si:1]([C:4]([CH3:5])([CH3:7])[CH3:6])([CH3:3])[CH3:2])[CH3:13])[CH3:11])[CH:44]=[C:45]([F:47])[CH:46]=1)[C:34]1[CH:39]=[CH:38][CH:37]=[CH:36][CH:35]=1

Participants

10

Reactant 7

HCID 179AcetoinHCID 795ImidazoleHCID 28928tert-Butyldimethylsilyl chlorideHCID 5462224MagnesiumHCID 110418312-Butanone, 3-[[(1,1-dimethylethyl)dimethylsilyl]oxy]-HCID 112545161-(Benzyloxy)-3-bromo-5-fluorobenzeneHCID 178505958HCID 178505958, compound

Product 1

HCID 19761503(2RS,3SR)-2-(3-benzyloxy-5-fluorophenyl)-3-(tert-butyldimethylsilyloxy)butan-2-olYield 41%

Reagents, catalysts & solvents 2

HCID 3283Diethyl EtherSolventHCID 8028TetrahydrofuranSolvent3×

Procedure

A solution of 3-tert-butyldimethylsilyloxybutan-2-one (5.56 g; prepared by reacting 3-hydroxybutan-2-one with tert-butyldimethylsilyl chloride in diethyl ether and using imidazole as a suitable base) in tetrahydrofuran (5 ml) was added to a solution of 3-benzyloxy-5-fluorophenylmagnesium bromide [prepared by heating a mixture of benzyl 3-bromo-5-fluorophenyl ether (6.7 g), magnesium powder (0.58 g) and tetrahydrofuran (50 ml) to 40° C. for 1 hour] in tetrahydrofuran (50 ml) and the mixture was stirred at ambient temperature for 2.5 hours. The mixture was evaporated and the residue was partitioned between diethyl ether and water. The organic phase was washed with a saturated aqueous sodium chloride solution, dried (MgSO4) and evaporated. The residue was purified by column chromatography using a 3:2 v/v mixture of petroleum ether (b.p. 40°-60° C.) and methylene chloride as eluent. There was thus obtained an erythro isomer, (2RS,3SR)-2-(3-benzyloxy-5-fluorophenyl)-3-(tert-butyldimethylsilyloxy)butan-2-ol (3.8 g, 41%), as an oil; and a threo isomer, the corresponding (2RS,3RS)-isomer (1.73 g, 18%), as an oil.

Workup

  1. customprepared
  2. customprepared
  3. temperatureby heating
  4. customThe mixture was evaporated
  5. customthe residue was partitioned between diethyl ether and water
  6. washThe organic phase was washed with a saturated aqueous sodium chloride solution
  7. dry with materialdried (MgSO4)
  8. customevaporated
  9. customThe residue was purified by column chromatography
  10. additiona 3:2 v/v mixture of petroleum ether (b.p. 40°-60° C.) and methylene chloride as eluent

Sources & evidence

ORD record
ord-e61d108b381d448db01eb88ed1f872d3
Source dataset
uspto-grants-1993_05
Patent number
US05214069

Linked notes

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