Sodium hydride → [(R)-2-(2,2-diethoxyethoxy)-4-pentenyloxymethyl]benzene

Participants

Reaction Steps

This reaction was carried out in two identical experiments. To a 0° C. suspension of sodium hydride (60% in mineral oil, 124.8 g, 3.12 mol) in tetrahydrofuran (1 L) was added a solution of (2R)-1-(benzyloxy)pent-4-en-2-ol (C1) (200 g, 1.04 mol) in tetrahydrofuran (500 mL). The reaction was stirred for 30 minutes at room temperature, whereupon 2-bromo-1,1-diethoxyethane (528 g, 2.68 mol) was added, and the reaction mixture was heated at reflux for 18 hours. The mixture was carefully quenched with water (2×300 mL) and the combined experiments were concentrated in vacuo. The aqueous residue was partitioned between ethyl acetate (5 L) and water (5 L). The organic layer was washed with saturated aqueous sodium chloride solution (5 L), dried, and concentrated. Purification via silica gel chromatography (Eluent: 20:1 petroleum ether/ethyl acetate) provided the product as a yellow oil. Yield: 300 g, 0.97 mol, 47%. 1H NMR (400 MHz, CDCl3) δ 7.26-7.37 (m, 5H), 5.78-5.90 (m, 1H), 5.01-5.13 (m, 2H), 4.61 (t, J=5.3 Hz, 1H), 4.55 (s, 2H), 3.48-3.74 (m, 9H), 2.30-2.36 (m, 2H), 1.22 (t, J=7.1 Hz, 3H), 1.21 (t, J=7.0 Hz, 3H).

Provenance & Evidence