2-Methoxypropene → HCID 69280805, compound

To a solution of 154 (3.0 g, 8.5 mmol) in DMF (20 mL) was added 4-methylbenzenesulfonic acid hydrate (3.2 g, 17 mmol) and 2-methoxyprop-1-ene (6.1 g, 85 mmol) sequentially. The resulting solution was stirred for 15 minutes at room temperature, before the reaction was quenched by the addition of saturated aqueous sodium bicarbonate solution (20 mL), which was then extracted with dichloromethane (3×20 mL). The combined organic layer was washed with brine (2×10 mL), dried over sodium sulfate, filtered and concentrated under vacuum. The crude residue was purified by flash column chromatography with 1%-10% ethyl acetate in petroleum ether to afford 155 as an off-white solid (1.6 g, 48%). (ES, m/z): [M+H]+ 393.0; 1H NMR (300 MHz, CDCl3) δ 8.08-8.05 (m, 2H), 7.63-7.45 (m, 3H), 6.32-6.30 (m, 1H), 4.60-4.52 (m, 2H), 4.41-4.31 (m, 2H), 3.97-3.91 (m, 1H), 3.70-3.63 (m, 1H), 3.55-3.50 (m, 1H), 3.39-3.30 (m, 1H), 3.10 (s, 6H), 1.50 (s, 6H).