Sodium Hydroxide → 4-((1R,3aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-3a-((2-carboxycyclopropyl)methylamino)-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

Participants

Reaction Conditions

Reaction Steps

To a solution of methyl 4-((1R,3aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-3a-((2-(ethoxycarbonyl)cyclopropyl)methylamino)-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 (33 mg, 0.049 mmol) in 1,4-dioxane (2 mL) was added NaOH (1N) (0.246 mL, 0.246 mmol). The mixture was heated to 85° C. for 22 h then was cooled to rt. An additional 0.25 mL of 1N NaOH was added to the mixture and it was again heated to 85° C. After stirring the mixture over the weekend, the reaction mixture was purified by prep HPLC. The fractions containing the expected product were combined and concentrated under reduced pressure. 1H NMR still showed impurities present, so the mixture was purified a second time by prep HPLC. The fractions containing the product were combined and concentrated under reduced pressure to give the title compound (8.3 mg, 0.012 mmol, 24.15% yield) as a white solid. LCMS: m/e 628.6 (M+H)+, 1.66 min (method 2).

Provenance & Evidence