2-(3-Oxo-5-phenyl-trans-1-pentenyl)-3-(5-carboethoxypentyloxy)-4-pyrone → 2-[(3RS)-3-hydroxy-5-phenyl-trans-1-pentenyl]-3-(5-carboethoxypentyloxy)-4-pyrone

HRID 2163268Notes

Reaction equation

HRID 2163268 reaction equation
[O:1]=[C:2]([CH2:23][CH2:24][C:25]1[CH:30]=[CH:29][CH:28]=[CH:27][CH:26]=1)/[CH:3]=[CH:4]/[C:5]1[O:6][CH:7]=[CH:8][C:9](=[O:22])[C:10]=1[O:11][CH2:12][CH2:13][CH2:14][CH2:15][CH2:16][C:17]([O:19][CH2:20][CH3:21])=[O:18].C([BH-](CC)CC)C.[Li+]>O1CCCC1>[OH:1][CH:2]([CH2:23][CH2:24][C:25]1[CH:26]=[CH:27][CH:28]=[CH:29][CH:30]=1)/[CH:3]=[CH:4]/[C:5]1[O:6][CH:7]=[CH:8][C:9](=[O:22])[C:10]=1[O:11][CH2:12][CH2:13][CH2:14][CH2:15][CH2:16][C:17]([O:19][CH2:20][CH3:21])=[O:18]

Participants

4

Reactant 2

HCID 233448642-(3-Oxo-5-phenyl-trans-1-pentenyl)-3-(5-carboethoxypentyloxy)-4-pyroneHCID 23664628Lithiumtriethylborohydride

Product 1

HCID 233448652-[(3RS)-3-hydroxy-5-phenyl-trans-1-pentenyl]-3-(5-carboethoxypentyloxy)-4-pyroneYield 28.2%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To a solution, cooled under nitrogen to -78°, of 0.823 g (1.99 mmol) of 2-(3-oxo-5-phenyl-trans-1-pentenyl)-3-(5-carboethoxypentyloxy)-4-pyrone in 4 ml of tetrahydrofuran was added dropwise keeping the internal temperature at -70° to -75°, 1.89 ml (1.89 mmole) of lithium triethylborohydride. After being stirred for an additional 30 min the cold reaction was quenched by the addition of 2.0 ml of 40% aqueous acetic acid and then partially concentrated under reduced pressure. The residue was dissolved in methylene chloride and washed successively with aqueous sodium bicarbonate and brine solution. The organic solution was dried over magnesium sulfate and evaporated to give an oil. Chromatographic purification on silica gel eluting with ether furnished 0.233 g (28%) of 2-[(3RS)-3-hydroxy-5-phenyl-trans-1-pentenyl]-3-(5-carboethoxypentyloxy)-4-pyrone. NMR (CDCl3, 100 M Hz): δ1.26 (3H, t, J = 7.0 Hz), 2.32 (2H, t, J = 6 Hz).

Workup

  1. additionwas added dropwise
  2. customat -70° to -75°
  3. customthe cold reaction
  4. customwas quenched by the addition of 2.0 ml of 40% aqueous acetic acid
  5. concentrationpartially concentrated under reduced pressure
  6. dissolutionThe residue was dissolved in methylene chloride
  7. washwashed successively with aqueous sodium bicarbonate and brine solution
  8. dry with materialThe organic solution was dried over magnesium sulfate
  9. customevaporated
  10. customto give an oil
  11. customChromatographic purification on silica gel eluting with ether

Sources & evidence

ORD record
ord-e9d53a5cfab94f5ba0000594b2d7ed5a
Source dataset
uspto-grants-1979_01
Patent number
US04132847

Reaction notes

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