Propargyl alcohol → Tetrahydro-2-(2-propynyloxy)-2H-pyran

Participants

Reaction Conditions

Reaction Steps

At 0° C., 3,4-dihydro-2H-pyran (173 ml, 1.90 mol) is added dropwise over 10 min to a soln. of propargyl alcohol (88.49 g, 1.58 mol) and TsOH.H2O (16.08 g, 84.53 mmol) in CH2Cl2 (880 ml). After stirring for 80 min at 0° C., the mixture is warmed to room temperature, stirred for 3 h, treated with Et3N (12 ml), and evaporated. A vacuum distillation (20 mmHg, 80° C.) gives C (224 g, quant.). Colourless oil. 1H-NMR (400 MHz, CDCl3) δ 1.46-1.70 (m, 4 H), 1.70-1.91 (n, 2 H), 2.41 (t, J=2.2), 3.49-3.58 (m, 1 H), 3.81-3.88 (m, 1 H), 3.49-3.58 (m, 1 H), 4.23 (dd, J=15, 2.2), 4.30 (dd, J=15, 2.2), 4.83 (t, J=3.0).

Provenance & Evidence