3,4-dihydro-2H-pyran → 2-(3-Butynyloxy)tetrahydro-2H-pyran

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Reaction Steps

A solution of 3-butyn-1-ol (3.0 g, 0.042 mol) and 3,4-dihydropyran (4.20 g, 0.05 mol) in hexane (10 ml) (Bongini et. al., Synthesis, 618, 1979), is added to a suspension of Dowex (1.5 g) in hexane (10 ml) and the mixture is stirred for 1 hr at room temperature. The resin is filtered off and the solvent removed in vacuo. The crude residue is purified by flash chromatography using hexane/ethyl acetate (9:1, v/v) to give 3-butyn-1-yl tetrahydropyranyl ether (6.47 g, 97%) as a colorless liquid: Rf=0.25; Hexane/ethyl acetate (1:1, v/v) IR (film) ν3300 (C≡C--H), 2160 (C≡C); and 1H NMR (CDCl3) δ1.48 (m, 6H), 1.88 (t, J=3 Hz, 1H), 2.35 (m, 2H), 3.60 (m, 4H), 4.56 (br S, 1H).

Provenance & Evidence