Tetrahydrofuran → 1,1-Bis(3,5-dimethoxyphenyl)prop-2-yn-1-ol

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Reaction Steps

In a 100 mL flask, bis(3,5-dimethoxy-phenyl)methanone (compound B, 1.2 g, 3.9 mmol) was dissolved in 20 mL diethyl ether. Approximately 5 mL THF was added to help solvate the ketone followed by the slow addition of ethynylmagnesium bromide (0.5 M in THF, 12 mL). The reaction was monitored by TLC and upon consumption of starting material, 2N HCl was added to the flask. The mixture was extracted 3 times with ethyl acetate and the combined organic layers were washed with brine, dried over anhydrous MgSO4, filtered, and concentrated to give a yellow oil. Purification was achieved with column chromatography using a gradient of 30% to 50% acetone/hexane. The product was obtained as a pale yellow oil in 73% yield: Rf 0.14 (30:70 acetone/hexane); IR (cm−1): 3441, 3280, 2940, 2837, 1598, 1460, 1289, 1205, 1156, 1053, 834, 748, 689; 1H NMR (250 MHz, C6D6): δ 2.38 (s, 1H), 2.94 (br s, 1H), 3.27 (s, 12H), 6.42 (t, J=2.5 Hz, 2H), 3.99 (d, J=2.5 Hz, 4H); 13C NMR (63 MHz, C6D6): 54.8 (4C), 74.5, 75.3, 86.8, 100.1 (2C), 104.9 (4C), 147.6 (2C), 161.2 (4C).

Provenance & Evidence