Pyridine → HCID 50924391, compound

Participants

Reaction Steps

To a stirred solution of ethyl 4-ethyl-1-((1R,3aS,5aR,5bR,7aR,9S,11aR,11bR,13aR,13bR)-9-hydroxy-5a,5b,8,8,11a-pentamethyl-1-(prop-1-en-2-yl)icosahydro-1H-cyclopenta[a]chrysene-3a-carbonyl)piperidine-4-carboxylate (Example 73, 0.5 g, 0.80 mmol) in pyridine (5 ml) dimethyl amino pyridine (0.2 g, 1.6 mmol) was added then 3,3-dimethyldihydrofuran-2,5-dione (0.82 ml) was added and the contents were refluxed for about 16 hours. Completion of the reaction was monitored by TLC, the reaction mixture was diluted with ethyl acetate (30 ml) and the organic layer was washed with 5% aqueous HCl, washed with water followed by brine, dried over Na2SO4 and concentrated under reduced pressure. The residue was purified by silica gel column chromatography using 5% MeOH in DCM as eluent to furnish the title compound (0.25 g) as a white solid. 1H NMR (300 MHz, CDCl3): 0.95-1.16 (m, 19H); 1.23-1.78 (m, 23H); 2.15-2.59 (m, 11H); 2.77-3.58 (m, 16H); 4.33-4.70 (m, 4H); 5.58-5.60 (s, 1H); 5.78-5.80 (s, 1H); 7.44-7.47 (s, 1H); ES Mass: 753; (100%), [M+1].

Provenance & Evidence