Synthesis of (7R,8R,9S,13S,14S,17S)-7-(9-bromononyl)-13-methyl-7,8,9,11,12,13,14,15,16,17-decahydro-6H-cyclopenta[a ]phenanthrene-3,17-diol was performed in the following general steps: the compound of Formula II (5.0 g) prepared in Example 1 was added to a reaction flask with methanol (50 mL) and heated until dissolved. Subsequently, aqueous hydrobromic acid (5 mL of 40 mL) was slowly added and the reaction was carried out at 60 °C for 2 hours. After completion of the reaction, it was cooled to room temperature and the solid product was collected by filtration. The resulting solid was dried in a vacuum oven at 40 °C for 8 h to afford the compound of formula III (4.3 g), which was tested to be 97.7% pure.
