p-Toluenesulfonic acid → 7alpha-(5-Acetoxypentyl)-11beta-fluoro-3-(tetrahydro-pyran-2-yloxy)oestra-1,3,5(10)-trien-17-one

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Reaction Steps

8.2 g of 7α-(5-acetoxypentyl)-11β-fluoro-3-hydroxyestra-1,3,5(10)-trien-17-one in 86 ml of THF are stirred at RT for 2.5 h with 8.6 ml of 3,4-dihydro-2H-pyran and 820 mg of p-toluenesulphonic acid. 0.5 ml of triethylamine is then added, and the mixture is diluted with ethyl acetate, washed with saturated sodium chloride solution, dried and concentrated in vacuo. After chromatographing the crude product on silica gel using a hexane-ethyl acetate gradient, 7.8 g of 7α-(5-acetoxypentyl)-11β-fluoro-3-(tetrahydropyran-2-yloxy) oestra-1,3,5(10)-trien-17-one are obtained as a foam.

Provenance & Evidence