(2S)-1-[(tert-butoxy)carbonyl]-4,4-difluoropyrrolidine-2-carboxylic acid → 4-((1R,3aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-3a-((S)-1-(tert-butoxycarbonyl)-4,4-difluoropyrrolidine-2-carboxamido)-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

Beteiligte Stoffe

Reaktionsschritte

The title compound was prepared in 29% yield from methyl 4-((1R,3aS,5aR,5bR,7aR,11aS,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)benzoate following the same procedure as described for the preparation of 4-((1R,3aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-3a-(3-(dimethylamino)propanamido)-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, except (S)-1-(tert-butoxycarbonyl)-4,4-difluoropyrrolidine-2-carboxylic acid was used instead of 3-(dimethylamino)propionic acid hydrochloride in Step 1. LCMS: m/e 763.5 (M+H)+, 2.55 min (method 6). 1H NMR (500 MHz, 1:1 CDCl3:MeOD) δ=7.92 (d, J=8.5 Hz, 2H), 7.20 (d, J=8.5 Hz, 2H), 6.46 (br. s., 1H), 5.29 (dd, J=1.7, 6.3 Hz, 1H), 4.72 (s, 1H), 4.63 (br. s., 1H), 4.50 (d, J=9.2 Hz, 1H), 3.84 (br. s., 1H), 3.72 (td, J=6.7, 13.4 Hz, 1H), 2.84 (br. s., 1H), 2.55 (d, J=13.4 Hz, 1H), 2.51-2.37 (m, 2H), 2.12 (dd, J=6.4, 17.1 Hz, 1H), 1.96 (br. s., 1H), 1.73 (br. s., 1H), 1.70 (s, 4H), 1.61 (br. s., 2H), 1.56 (br. s., 9H), 1.53-1.45 (m, 5H), 1.45-1.37 (m, 3H), 1.36-1.29 (m, 2H), 1.28-1.23 (m, 1H), 1.17-1.09 (m, 2H), 1.08 (s, 3H), 1.02 (s, 6H), 0.94 (s, 3H), 0.93 (s, 3H).

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