Reaction Steps
To a solution of methyl 4-((1R,3aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-3a-((2-fluoroethyl)amino)-5a,5b,8,8,11a-pentamethyl-1-(prop-1-en-2-yl)-2,3,3a,4,5,5a,5b,6,7,7a,8,11,11a,11b,12,13,13a,13b-octadecahydro-1H-cyclopenta[a]chrysen-9-yl)benzoate (0.059 g, 0.100 mmol) in 1,4-dioxane (2 mL) was added NaOH (1N) (0.5 mL, 0.500 mmol). The mixture was heated to 85° C. for 15.25 h, was cooled to rt, then was diluted with methanol and 1,4-dioxane and was purified by prep HPLC. The fractions containing the expected product were combined and concentrated under reduced pressure to give 4-((1R,3aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-3a-((2-fluoroethyl)amino)-5a,5b,8,8,11a-pentamethyl-1-(prop-1-en-2-yl)-2,3,3a,4,5,5a,5b,6,7,7a,8,11,11a,11b,12,13,13a,13b-octadecahydro-1H-cyclopenta[a]chrysen-9-yl)benzoic acid (29.2 mg, 0.048 mmol, 48.2% yield) as a white solid. LCMS: m/e 576.6 (M+H)+, 1.74 min (method 2). 1H NMR (400 MHz, Acetic acid d4) δ 7.99 (d, J=8.53 Hz, 2H), 7.26 (d, J=8.28 Hz, 2H), 5.33 (d, J=4.77 Hz, 1H), 4.73-4.99 (m, 3H), 4.70 (s, 1H), 3.41-3.73 (m, 2H), 2.83-2.94 (m, 1H), 1.73 (s, 3H), 1.19 (s, 3H), 1.11 (s, 3H), 1.05 (s, 3H), 0.98 (s, 3H), 0.96 (s, 3H), 0.82-2.27 (m, 22H).
