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

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of propargyl alcohol (5g, 90 mmol) and dihydropyran (37.5 g, 0.44 mol, 5 equiv) in CH2Cl2 (300 ML), was added p-toluenesufonic acid (30 mg). The mixture was stirred at 20° C. for 1.5 hours. The solvent was removed by rotary evaporation. The residue was taken up in ether (150 mL) and washed with aqueous saturated NaHCO3 (120 mL), saturated NaCl (120 mL), water (200 mL). The organic layer was dried (MgSO4) and concentrated to yield a yellow oil. Purification by distillation under reduced pressure gave Tetrahydro-2-(2-propynyloxy)-2H-pyran (47) (12 g, 97%) as a colorless oil: bp: (40° C., 0.05 mm Hg). ##STR20##

Provenance & Evidence