PREPARATION OF 16-SUBSTITUTED 3-HYDROXYESTRA-1,3,5(10)-TRIENE-17-ONE STARTING WITH THE BROMINATION OF ESTRONE ACETATE

Article abstract of DOI:10.1007/BF00575701

The bromination of estrone acetate (Ia) leads to a mixture of acetates of 16α-bromo-16β-bromo-, and 16,16-dibromoestrone (IIa, IIIa, and IVa) in a ratio of 63:28:9.On treatment with an aqueous methanolic solution of potash, depending on the conditions, a mixture of (IIa) and (IIIa) gives 3,16α-dihydroxyestra-1,3,5(10)-trien-17-one (V) or 3,17β-dihydroxyestra-1,3,5(10)-trien-16-one (VI).When 5 g of (Ia) was brominated with 2.8 g of Br2 in chloroform and the products were chromatographed on silica gel, 0.36 g of (IVa), C20H22Br2O3, mp 165-166 deg C (from ether) 0.37 g of (IIIa), mp 169-170.5 deg C, 4.6 g of a mixture of (IIa) and (IIIa), 30 mg of (Ia) and 0.2 g of a mixture of 16α- and 16β-bromoestrones was obtained.The action of potash on a mixture of (IIa) and (IIIa) in aqueous MeOH at 20 deg C led to the epimerization of the (IIa) into (IIIa) and then the conversion of the latter into (V) with mp 203.5-206 deg C; diacetate with mp 172-173 deg C (acetone-ethanol).Similarly, but with heating (98 deg C, 3 h), a mixture of (IIa) and (IIIa) was converted into (VI), with mp 234-236 deg C.Characteristics of the IR and PMR spectra of the compounds obtained are given.