Tetrahydrofuran → 3-Methoxyestra-3,5(10)-dien-17beta-ol

Beteiligte Stoffe

Reaktionsschritte

3-Methoxyestra-2,5(10)-dien-17β-ol 1 (2.0 g, 6.9 mmol) was added to a solution consisting of tetrahydofuran (15 ml), DMSO (5 ml) and t-BuOK (20.7 mmol). The resultant solution was stirred at ambient temperature for 10 hours at which time the solution was concentrated to Å5 ml and chromatographically filtered with 50% ethylether/petroleum ether (light) through 10 g of silica gel. The subsequent dimethyl sulfoxide (DMSO) free -powder was flash chromatographed affording 4 as white needles (1.30 g, 65% conversion, 91% based on recovered 1), Alternatively, crystallization by selective seeding (ether/methanol) was utilized, thereby circumventing chromatographic purification. 1H NMR (d6-acetone) δ4.629 (s, 1H), 3.505 (t, J=8.09 Hz, 1H), 3.431 (s, 3H), 2.15-0.98 (complex, 20H), 0.644 (s, 3H). 13C NMR (CDCl3) δ156.71, 126.56, 123.88, 96.55, 81.31, 54.19, 50.18, 46.03, 39.91, 37.54, 30.64, 30.58, 30.21, 27.71, 27.17, 25.67, 25.24, 23.22, 11.37.

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