反应详情

To a stirred mixture of commercially available (S)-(−)-α{tilde over (α)}Diphenyl-2-pyrrolidinemethanol (0.83 g, 3.28 mmol) in toluene (40 mL) was added 2-nitrobenzoic acid (0.55 g, 3.28 mmol), commercially available 2-Hydroxybenzaldehyde (2.00 g, 16.38 mmol) and (E)-4-oxo-but-2-enoic acid ethyl ester (2.51 g, 19.65 mmol). After addition was complete the mixture was stirred at room temperature for 3 days. Upon completion of the reaction the toluene was removed by vacuum distillation. The residue was diluted with ethyl acetate and washed with water, a saturated sodium bicarbonate solution and a saturated sodium chloride solution. The organic fraction was then dried over magnesium sulfate. The crude product obtained was purified by ISCO flash chromatography (Teledyne Isco RediSep Flash Column 40 g; (0% to 100% ethyl acetate/hexane) to afford 3-formyl-2H-chromene-2-carboxylic acid ethyl ester as a yellow oil, 1.09 g (29% yield). (Ref: Chem. Eur. Journal; 2007, 13, pg 574).

1. additionAfter addition
2. customwas removed by vacuum distillation
3. additionThe residue was diluted with ethyl acetate
4. washwashed with water
5. dry with materialThe organic fraction was then dried over magnesium sulfate
6. customThe crude product obtained
7. customwas purified by ISCO flash chromatography (Teledyne Isco RediSep Flash Column 40 g