Benzyl Bromide → (E)-benzyl-2(R)-[1(S)-(tert-butoxycarbonyl)-4-phenyl-3-butenyl]-4-methylvalerate

HRID 1979252Notes

Reaction equation

HRID 1979252 reaction equation
[C:1]([O:5][C:6]([C@H:8]([C@@H:18]([CH2:22][CH:23]([CH3:25])[CH3:24])[C:19]([OH:21])=[O:20])[CH2:9]/[CH:10]=[CH:11]/[C:12]1[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1)=[O:7])([CH3:4])([CH3:3])[CH3:2].C(N(CC)CC)C.[CH2:33](Br)[C:34]1[CH:39]=[CH:38][CH:37]=[CH:36][CH:35]=1>C(OCC)(=O)C>[CH2:33]([O:20][C:19](=[O:21])[C@@H:18]([C@@H:8]([C:6]([O:5][C:1]([CH3:4])([CH3:3])[CH3:2])=[O:7])[CH2:9]/[CH:10]=[CH:11]/[C:12]1[CH:13]=[CH:14][CH:15]=[CH:16][CH:17]=1)[CH2:22][CH:23]([CH3:25])[CH3:24])[C:34]1[CH:39]=[CH:38][CH:37]=[CH:36][CH:35]=1

Participants

5

Reactant 3

HCID 7498Benzyl BromideHCID 8471TriethylamineHCID 11418712(E)-2(R)-[1(S)-(tert-butoxycarbonyl)-4-phenyl-3-butenyl]-4-methylvaleric acid

Product 1

HCID 69953806(E)-benzyl-2(R)-[1(S)-(tert-butoxycarbonyl)-4-phenyl-3-butenyl]-4-methylvalerateYield 41.8%

Reagents, catalysts & solvents 1

HCID 8857Ethyl AcetateSolvent

Procedure

A solution of 30 g of (E)-2(R)-[1(S)-(tert-butoxycarbonyl)-4-phenyl-3-butenyl]-4-methylvaleric acid in 400 ml of ethyl acetate was treated with 9.63 g of triethylamine and 16.31 g of benzyl bromide and then heated at reflux for 4 hours. On cooling the mixture to room temperature filtration and evaporation of the filtrate gave a residue which was purified by column chromatography on silica gel, using ethyl acetate/hexane (1:9) for the elution, to give 15.8 g of (E)-benzyl-2(R)-[1(S)-(tert-butoxycarbonyl)-4-phenyl-3-butenyl]-4-methylvalerate in the form of a clear oil.

Workup

  1. temperatureheated
  2. temperatureat reflux for 4 hours
  3. filtrationfiltration and evaporation of the filtrate
  4. customgave a residue which
  5. customwas purified by column chromatography on silica gel
  6. washfor the elution

Sources & evidence

ORD record
ord-469a1439e25542379e7019b1abe84857
Source dataset
uspto-grants-2001_05
Patent number
US06239151B1

Reaction notes

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