3,4-dihydro-2H-pyran → 2-(6-Bromo-2-methyl-2-p-tolylhexyloxy)-tetrahydropyran

Participants

Reaction Steps

Under N2 atmosphere, 3,4-dihydro-2H-pyran (6.39 g, 76.09 mmol) was added drop-wise to a stirred solution of 6-bromo-2-methyl-2-p-tolyl-hexan-1-ol (18.20 g, 63.86 mmol) and p-toluenesulfonic acid hydrate (0.43 g, 2.26 mmol) in dichloromethane (300 mL) at −5° C. The reaction mixture was allowed to warm to rt and stirred for 3 h. The solution was filtered through aluminum oxide (160 g), which was washed with CH2Cl2 (500 mL). The filtrate was concentrated in vacuo to furnish 2-(6-bromo-2-methyl-2-p-tolyl-hexyloxy)-tetrahydropyran (22 g, 93.4%) as an oil. 1H NMR (300 MHz, CDCl3/TMS): δ (ppm) 7.25-7.05 (m, 4H), 4.60-4.48 (m, 1H), 3.82 (m, 2H), 3.48-3.37 (m, 2H), 3.35-3.26 (m, 2H), 2.30 (s, 3H), 1.90-1.40 (m, 11H), 1.40-1.33 (s, 3H), 1.40-1.08 (m, 1H), 13C NMR (75 MHz, CDCl3/TMS): δ (ppm) 142.78, 135.22, 128.81, 126.39, 99.09, 61.99, 41.67, 38.12, 37.87, 33.68, 30.99, 25.96, 23.08, 22.89, 21.12, 20.97, 19.41. HRMS (LSIMS, nba): Calcd. for C19H30O2Br (MH+): 369.1429, found: 369.1451.

Provenance & Evidence