To a solution of (1S,3aS,5aR,5bR,7aR,9S,11aR,11bR,13aR,13bR)-9-hydroxy-1-isopropyl-5a,5b,8,8,11a-pentamethylicosahydro-1H-cyclopenta[a]chrysene-3a-carboxylic acid (3 g, 6.54 mmol) and potassium carbonate (1.808 g, 13.08 mmol) in DMF (60 mL) was added (bromomethyl)benzene (0.816 mL, 6.87 mmol). The reaction mixture was heated up to 60° C. for 3 h. LCMS indicated the starting material was consumed. The reaction mixture was quenched with 60 ml water, a white precipitate was observed. The white solid was collected through filtration and washed with distilled water. The solid was dried in the air to provide the title compound as white solid (3.3 g, 92%). 1H NMR (500 MHz, CHLOROFORM-d) δ ppm 7.42-7.28 (m, 5H), 5.27-5.01 (m, 2H), 3.18 (dt, J=11.22, 5.53 Hz, 1H), 2.40-2.09 (m, 3H), 1.91-1.73 (m, 2H), 1.72-0.78 (m, 21H), 0.95 (s, 3H), 0.91 (s, 3H), 0.84 (d, J=7.02 Hz, 3H), 0.80 (s, 3H), 0.75 (s, 3H), 0.73 (s, 3H), 0.73 (d, J=6.71 Hz, 3H).
