Reaction Steps
To a solution of ethyl 1-((tert-butoxycarbonyl)amino)-2-((E)-2-((1R,3aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-3a-((2-(1,1-dioxidothiomorpholino)ethyl)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)vinyl)cyclopropanecarboxylate (12 mg, 0.015 mmol) in dioxane (2 mL) and MeOH (1 mL) was added 1N NaOH (1 mL, 1 mmol). The mixture was stirred at 25° C. for 2 h. The crude product was purified by prep HPLC (method 4) to give 1-((tert-butoxycarbonyl)amino)-2-((E)-2-((1R,3aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-3a-((2-(1,1-dioxidothiomorpholino)ethyl)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)vinyl)cyclopropanecarboxylic acid as a white solid (1 mg, 8.63%). MS: m/e 796.55 (M+H)+, 2.57 min (method 2). 1H NMR (400 MHz, METHANOL-d4) δ 7.37-5.41 (m, 2H), 5.36-5.10 (m, 1H), 4.73 (br. s., 1H), 4.57 (br. s., 1H), 3.19-2.97 (m, 8H), 2.80-2.62 (m, 4H), 2.58-2.41 (m, 1H), 2.36-1.78 (m, 7H), 1.72 (s, 3H), 1.69-1.21 (m, 25H), 1.16 (m, 6H), 1.09-1.00 (m, 6H), 0.98-0.82 (m, 6H).
