Boronic Acid → 5-[(1R,3aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-3a-carboxy-1-isopropenyl-5a,5b,8,8,11a-pentamethyl-1,2,3,4,5,6,7,7a,11,11b,12,13,13a,13b-tetradecahydrocyclopenta[a]chrysen-9-yl]thiophene-2-carboxylic acid

Participants

Reaction Steps

The title compound was prepared following the method described above for compound (1R,3aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-9-(4-(2-carboxyethyl)phenyl)-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]chrysene-3a-carboxylic acid (example 4a) using 5-boronothiophene-2-carboxylic acid as the reactant boronic acid. The product was isolated as a white solid (4.15 mg, 23%). LCMS: m/e 563.53 (M−H)−, 2.94 min (method 4). 1H NMR (400 MHz, <DMSOmix>) δ ppm 0.90 (br. s., 3H), 0.96 (s, 3H), 0.98 (s, 3H), 1.04 (s, 3H), 1.06 (s, 3H), 1.09-1.76 (m, 17H), 1.68 (s, 3H), 1.80-1.94 (m, 2H), 2.10-2.23 (m, 2H), 2.25-2.40 (m, 1H), 2.91-3.05 (m, 1H), 4.58 (br. s., 1H), 4.71 (br. s., 1H), 5.75 (d, J=5.86 Hz, 1H), 6.90 (d, J=3.22 Hz, 1H), 7.51 (br. s., 1H).

Provenance & Evidence