Allyl bromide → HCID 86748026, compound

HRID 1729325Notes

Reaction equation

HRID 1729325 reaction equation
C(N[C@H](C(O)=O)CC(C)C)(OC(C)(C)C)=[O:2].[CH2:17]([O:24][C:25](=[O:42])[CH:26]([C:35]([O:37][C:38]([CH3:41])([CH3:40])[CH3:39])=[O:36])[N:27]([C:31]([CH3:34])([CH3:33])[CH3:32])[CH2:28][CH:29]=[CH2:30])[C:18]1[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=1.C(Br)C=C>C1COCC1>[CH2:17]([O:24][C:25](=[O:42])[CH:26]([C:35]([O:37][C:38]([CH3:41])([CH3:40])[CH3:39])=[O:36])[N:27]([C:31]([CH3:32])([CH3:33])[CH3:34])[CH2:28][CH2:29][CH2:30][OH:2])[C:18]1[CH:19]=[CH:20][CH:21]=[CH:22][CH:23]=1

Participants

5

Reactant 3

HCID 7841Allyl bromideHCID 83170L-Leucine, N-((1,1-dimethylethoxy)carbonyl)-HCID 131718564HCID 131718564, compound

Product 1

HCID 86748026HCID 86748026, compound

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

BOC-L-leucine is converted to racemic BOC-(2-isobutyl)-allyl glycine benzyl ester using essentially the procedures of Example 20, Steps A and B, substituting allyl bromide in the alkylation step. The benzyl ester (2.07 g, 5.73 mmol) is dissolved in THF (40 ml), under nitrogen, 0.5M 9-borabicyclo[3.3.1]-nonane (9-BBN)in hexanes (46 ml, 23 mmol) is added and mixture stirred at room temperature for 16 hours. The reaction mixture is quenched with water (1 ml) and a mixture of 1N aqueous sodium hydroxide solution (51 ml) and 30% hydrogen peroxide solution (18 ml) is added dropwise. The mixture is stirred for 1 hour at room temperature, saturated with solid sodium chloride, then extracted with ether. The organic layer is washed with saturated sodium bicarbonate solution, brine, dried over magnesium sulfate, filtered, and concentrated in vacuo. The crude product is purified by flash chromatography, eluting with 20% ethyl acetate/hexanes to give BOC-(2-isobutyl)-3-hydroxypropyl glycine benzyl ester.

Workup

  1. customThe reaction mixture is quenched with water (1 ml)
  2. additiona mixture of 1N aqueous sodium hydroxide solution (51 ml) and 30% hydrogen peroxide solution (18 ml)
  3. additionis added dropwise
  4. stirringThe mixture is stirred for 1 hour at room temperature, saturated with solid sodium chloride
  5. extractionextracted with ether
  6. washThe organic layer is washed with saturated sodium bicarbonate solution, brine
  7. dry with materialdried over magnesium sulfate
  8. filtrationfiltered
  9. concentrationconcentrated in vacuo
  10. customThe crude product is purified by flash chromatography
  11. washeluting with 20% ethyl acetate/hexanes

Sources & evidence

ORD record
ord-76443711712f4ab0a9da9aad6b5907d0
Source dataset
uspto-grants-1994_07
Patent number
US05332726

Reaction notes

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