Ethylene Oxide → 7-[(tetrahydro-2H-pyran-2-yl)oxy]-3-heptyn-1-ol

Participants

Reaction Conditions

Reaction Steps

To a cooled solution (-20° C.) of tetrahydro- 2-(4-pentynyloxy)-2H-pyran (1) (16.8 g. 0.10 mole) and tetramethylethylene diamine (45.2 mL, 0.30 mole, distilled from CaH2 under nitrogen) in anhydrous tetrahydrofuran (100 mL. distilled from sodium/benzophenone under nitrogen) was added via syringe a solution of n-butyllithium (41.0 mL, 0.101 mole, 2.44 N in hexane). The mixture was allowed to warm to 0° C. over 30 minutes and stirred at 0° C. for 1 h followed by the addition, via cannula, of ethylene oxide (8 8 g, 0.20 mole, freshly condensed into an argon filled graduated cylinder). The solution was stirred at 0° C. for 1 h and then stored in a refrigerator (5° C.) for 3 days. The reaction mixture was poured into water (200 mL) and extracted with ether (1×200 mL, 2×50 mL). The organic layers were combined and washed with water (5×50 mL), saturated sodium chloride (50 mL), dried (MgSO4), and concentrated to provide 22.80 g of a crude amber oil which was chromatographed (ethyl acetate/hexane 1:1) to provide 12.09 g (59%) of the title compound: Rf =0.32 (ethyl acetate/hexane:1/1) 1H PMR (CDCl3); δ 4.60 (t, J=3 Hz, 1H), 3.85 (m, 2H), 3.67 (t, J=6 Hz, 2H), 3.50 (m, 2H), 2.71 (bs, 1H), 2.40 (m, 4H), 2.29 (m, 2H), 1.78 (m, 4H), 1.52 (m, 4H); 13C NMR (CDCl3): 98.9, 81.5, 77.1, 65.9, 62.2, 61.3, 30.7, 29.0, 25.5, 23.1, 19.5, 15.7 ppm; IR (CHCl3): 3600, 3460 cm-1 ; Analysis calculated for C13H20O3 : C, 67.89; H, 9.50; Found: C, 67.96; H, 9 79.

Provenance & Evidence