反应详情

The solution of 9.85 g of 4-methyl-3-nitrobenzyl alcohol in 200 ml of dichloromethane is admixed successively with 10.9 ml of 3,4-dihydro-2H-pyran and 1.12 g of p-toluenesulphonic acid monohydrate. The reaction mixture is stirred at room temperature over 18 hours. The solution is poured onto 1M sodium hydrogencarbonate solution (300 ml) and extracted with tert-butyl methyl ether (2×300 ml). The organic phase is washed with brine (300 ml), dried over sodium sulphate, filtered and concentrated by evaporation. The title compound is obtained as a colourless oil from the residue by means of flash chromatography (SiO2 60F). Rf=0.49 (1:2 EtOAc-heptane); Rt=4.73.

1. extractionextracted with tert-butyl methyl ether (2×300 ml)
2. washThe organic phase is washed with brine (300 ml)
3. dry with materialdried over sodium sulphate
4. filtrationfiltered
5. concentrationconcentrated by evaporation