3,4-dihydro-2H-pyran → 7alpha-(5-Acetoxypentyl)-11beta-fluoro-3-(tetrahydro-pyran-2-yloxy)oestra-1,3,5(10)-trien-17-one

Participants

Reaction Steps

8.2 g of 7α-(5-acetoxypentyl)-11β-fluoro-3-hydroxy-estra-1,3,5(10)-trien-17-one in 86 ml of THF is stirred with 8.6 ml of 3,4-dihydro-2H-pyran and 820 mg of p-toluenesulfonic acid hydrate for 2.5 hours at room temperature. Then, 0.5 ml of triethylamine is added, it is diluted with ethyl acetate, washed with saturated sodium chloride solution, dried and concentrated by evaporation in a vacuum. After the crude product is chromatographed on silica gel with a hexane-ethyl acetate gradient, 7.8 g of 7α-(5-acetoxypentyl)-11β-fluoro-3-(tetrahydropyran-2-yloxy)-estra-1,3,5(10)-trien-17-one is obtained as foam.

Provenance & Evidence