Reaction Steps
To a solution of 4-((1R,3aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-3a-((3-((S)-2-(methoxycarbonyl)pyrrolidin-1-yl)-3-oxopropylamino)methyl)-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 (10 mg, 0.014 mmol) in dioxane (1 ml) and methanol (2 ml) was added 1N sodium hydroxide (0.08 ml, 0.08 mmol) and H2O (0.5 ml). The resulting mixture was stirred at rt for 45 h. The reaction mixture was neutralized with 1N HCl and concentrated in vacuo. The residue was purified by prep. HPLC to afford the title compound (8.5 mg, 85%). MS: m/e 713.5 (MH+), 1.68 min (method 2). 1H NMR (400 MHz, MeOD) δ ppm 0.95 (s, 3H) 0.97 (s, 3H) 1.04 (s, 3H) 1.08 (s, 3H) 1.18 (s, 3H) 1.73 (s, 3H) 0.87-1.86 (m, 20H) 1.99-2.10 (m, 4H) 2.15 (dd, J=17.32, 6.53 Hz, 1H) 2.24-2.33 (m, 1H) 2.52 (td, J=9.60, 4.14 Hz, 1H) 2.83-2.92 (m, 3H) 3.24-3.28 (m, 1H) 3.38 (t, J=6.15 Hz, 2H) 3.52-3.68 (m, 2H) 4.48 (dd, J=8.41, 3.39 Hz, 1H) 4.64 (s, 1H) 4.76 (d, J=1.76 Hz, 1H) 5.30 (dd, J=6.15, 1.63 Hz, 1H) 7.21 (d, J=8.53 Hz, 2H) 7.91 (d, J=8.28 Hz, 2H).
