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

Beteiligte Stoffe

Reaktionsschritte

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).

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