Pyridine → 7-Methyl-14,15-methyleneestr-4-en-3-one

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Reaction Steps

A solution of (7α,14β,15β,17α)-17-(hydroxymethyl)-7-methyl-14,15-methyleneestr-4-en-3-one (Example 1, 0.20 g) in a mixture of dry pyridine (1.76 ml) and dry tetrahydrofuran (8.8 ml) was treated with acetic anhydride (1.06 ml). The mixture was stirred at room temperature overnight and then quenched with water. After 1 h stirring the product was extracted into ethyl acetate. The combined organic phases were washed with brine, dried over sodium sulfate, and concentrated under reduced pressure to give (7α,14β,15β,17α)17-[(acetyloxy)methyl)]-7-methyl-14,15-methyleneestr-4-en-3-one (0.22 g). 1H NMR (CDCl3) δ5.80 (t, 1H, J=2.8 Hz), 4.05 (dd, part A of AB system, 1H, J=11.0 and 6.3 Hz), 3.95 (dd, part B of AB system, 1H, J=11.0 and 7.1 Hz), 2.03 (s, 3H), 1.08 (s, 3H),. 0.62 (d, 3H, J=7.1 Hz), 0.48 (dd, 1H, J=8.3 and 5.1 Hz), 0.27 (dd, 1H, J=5.1 and 3.5 Hz).

Provenance & Evidence