反应详情

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).

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