反应详情

A solution of 1-[5-(hydroxymethyl)-1,2-oxazol-3-yl]ethanone (252 mg, 1.79 mmol), 3,4-dihydro-2H-pyran (0.24 ml, 2.68 mmol) and pyridinium 4-methylbenzenesulfonate (44.69 mg, 0.18 mmol) in DCM (10 mL) was stirred at RT for 16 hr and then for a further 0.5 hr at 40° C. after the addition of more 3,4-dihydro-2H-pyran (0.24 ml, 2.68 mmol) and pyridinium 4-methylbenzenesulfonate (44.69 mg, 0.18 mmol). The reaction mixture was diluted with water (5 ml) and the solution extracted with DCM (2×20 ml). The combined organic layers were washed with brine (5 ml), dried (Na2SO4), filtered and evaporated in vacuo. The crude product was purified by flash chromatography (Isolute, 9:1 heptane:EtOAc) to give the title intermediate: 1H NMR (500 MHz, CDCl3) delta 1.56-1.53 (2H, m), 1.68-1.60 (2H, m), 1.89-1.69 (2H, m), 2.65 (3H, s), 3.62-3.51 (1H, m), 3.93-3.78 (1H, m), 4.68 (1H, d, J=13.9 Hz), 4.75 (1H, t, J=3.3 Hz), 4.86-4.80 (1 H, m), 6.63 (1H, s).

1. extractionthe solution extracted with DCM (2×20 ml)
2. washThe combined organic layers were washed with brine (5 ml)
3. dry with materialdried (Na2SO4)
4. filtrationfiltered
5. customevaporated in vacuo
6. customThe crude product was purified by flash chromatography (Isolute, 9:1 heptane:EtOAc)