反应详情

To a solution, under nitrogen, of 0.187 g (3.9 mmole) of sodium hydride (50% dispersion in mineral oil) in 10 ml of dry THF was added dropwise 1.2 g (4.95 mmole) of dimethyl (2-oxo-4-phenylbutyl)-phosphonate. The heterogeneous mixture was stirred for 1.0 hour then a solution of 1.0 g (3.54 mmole) of 2-formyl-3-(5-carboethoxypentyloxy)-4-pyrone, prepared by the procedure of Examples 1 and 2, in 5 ml of THF was added. The mixture was stirred for 15 min then was neutralized to pH 7 with glacial acetic acid. The neutralized solution was concentrated by rotary evaporation and the residue dissolved in methylene chloride. The organic solution was washed with saturated brine solution and dried over magnesium sulfate. Removal of the solvent left an oil which was purified by chromatography on silica gel using ether as the eluent. Concentration of the fractions containing product furnished 0.90 g (64%) of pure 2-(3-oxo-5-phenyl-trans-1-pentenyl)-3-(5-carboethoxypentyloxy)-4-pyrone, m.p. 38.5-40°. NMR (CDCl3): δ1.26 (3H, t, J = 7 Hz); 2.35 (2H, t, J = 6.5 Hz).

1. additionwas added
2. stirringThe mixture was stirred for 15 min
3. concentrationThe neutralized solution was concentrated by rotary evaporation
4. dissolutionthe residue dissolved in methylene chloride
5. washThe organic solution was washed with saturated brine solution
6. dry with materialdried over magnesium sulfate
7. customRemoval of the solvent
8. waitleft an oil which
9. customwas purified by chromatography on silica gel
10. additionConcentration of the fractions containing product