反应详情

To a mixture of methyl 2-hydroxy-2-methylpropanoate (5.04 g, 42.7 mmol) and 3,4-dihydro-2H-pyran (5.85 ml, 64.0 mmol) in dichloromethane (40 ml) was added pyridine 4-methylbenzenesulfonate (0.536 g, 2.13 mmol) and the reaction mixture was stirred for 1.5 hours. The reaction mixture was poured into water and extracted with Et2O. The organic layers were dried over Na2SO4 filtered, and concentrated in vacuo to give a crude oil. The crude residue was purified by silica gel chromatography (hexane/ethyl acetate, 100:0 to 17:3) to afford methyl 2-methyl-2-(tetrahydro-2H-pyran-2-yloxy)propanoate (7.30 g, 36.1 mmol, 85% yield) as a colorless oil. 1H NMR (400 MHz, DMSO-d6) δ ppm 1.35 (s, 3H) 1.36-1.55 (m, 7H) 1.57-1.81 (m, 2H) 3.32-3.42 (m, 1H) 3.62 (s, 3H) 3.72-3.85 (m, 1H) 4.65-4.75 (m, 1H).

1. extractionextracted with Et2O
2. dry with materialThe organic layers were dried over Na2SO4
3. filtrationfiltered
4. concentrationconcentrated in vacuo
5. customto give a crude oil
6. customThe crude residue was purified by silica gel chromatography (hexane/ethyl acetate, 100:0 to 17:3)