Reaction Steps
The title compound was prepared as a mixture of diastereomers in 55.7% yield following the method for the preparation of Example 1, Step 1 described above, using (1R,3aS,5aR,5bR,7aR,11aR,11bR,13aR,13bR)-3a-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 trifluoromethanesulfonate and methyl 2-(3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)cyclopent-2-en-1-yl)acetate as the reactant. MS: m/e 531.5 (M−16)+, 2.69 min (method 3). 1H NMR (400 MHz, CHLOROFORM-d) δ 5.54 (s, 1H), 5.50-5.44 (m, 1H), 4.73 (s, 1H), 4.60 (s, 1H), 3.67 (s, 3H), 3.14 (t, J=7.0 Hz, 1H), 2.81-2.61 (m, 1H), 2.59-2.27 (m, 5H), 2.16-1.96 (m, 4H), 1.79-1.18 (m, 20H), 1.09-1.02 (m, 11H), 0.96 (s, 3H), 0.85 (s, 3H).
