Acetic Acid → methyl 4-((1R,3aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-3a-(3-(tert-butoxycarbonylamino)propylamino)-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

Participants

Reaction Steps

Acetic acid (0.013 mL, 0.221 mmol) and tert-butyl 3-oxopropylcarbamate (38.2 mg, 0.221 mmol) were added to a solution of 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 (40 mg, 0.074 mmol) in EtOH (1 mL) and dioxane (1.0 mL) and the mixture was stirred for 2 h at rt. Sodium triacetoxyborohydride (78 mg, 0.368 mmol) was added and the reaction mixture was stirred at 20° C. for two hours. The reaction was quenched with a saturated aqueous solution of sodium bicarbonate (3 mL), washed with 0.1N HCl (5 mL) and brine (5 mL) and extracted with DCM (3×5 mL). All the extracts were combined, dried over sodium sulfate, filtered and concentrated under reduced pressure to provide the title compound as pale yellow oil (28 mg, 54%). LCMS: m/e 701.51 (M+H)+, 4.0 min (method 10).

Provenance & Evidence