反应详情

To a solution of 5-bromo-2,2-dimethyl-1-pentanol (78 g, 0.35 mol) and p-toluenesulfonic acid (0.42 g) in dichloromethane (0.5 L) was added 3,4-dihydro-2H-pyran (45 mL) slowly at 0° C. The reaction mixture was stirred at rt overnight, or until no more starting material was evidenced by TLC. The mixture was filtered through aluminum oxide and was washed with dichloromethane (300 mL). The filtrate was evaporated under vacuum to produce 5-bromo-1-(tetrahydropyranyloxy)-2,2-dimethylpentane (101 g, 94.7% yield) as a pale-yellow oil. 1H NMR (300 MHz, CDCl3/TMS): δ (ppm) 4.48-4.52 (m, 1H), 3.90-3.75 (m, 1H ), 3.50-3.35 (m, 4H), 2.95 (d, J=12 Hz, 1H), 1.90-1.20 (m, 10H), 0.90 (s, 6H). 13C NMR (75 MHz, CDCl3=77.0 ppm/TMS): δ (ppm) 99.2, 76.3, 62.0, 38.0, 34.9, 34.2, 30.7, 28.0, 25.7, 24.8, 24.7, 19.3.

1. filtrationThe mixture was filtered through aluminum oxide
2. washwas washed with dichloromethane (300 mL)
3. customThe filtrate was evaporated under vacuum