Hydrochloric Acid → 3-((1R,3 aS,5aR,5bR,7aR,11aS,11bR,13 aR,13bR)-3a-((2-((1R,4R)-2,2-dioxido-2-thia-5-azabicyclo[2.2.1]heptan-5-yl)ethyl)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)bicyclo[3.1.0]hex-2-ene-6-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

To a solution of ethyl 3-((1R,3aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-3a-((2-((1S)2,2-dioxido-2-thia-5-azabicyclo[2.2.1]heptan-5-yl)ethyl)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)bicyclo[3.1.0]hex-2-ene-6-carboxylate (28 mg, 0.03 mmol) in 1,4-dioxane (2 mL) was added sodium hydroxide (1N) (0.149 mL, 0.149 mmol). The mixture was warmed to 70° C. After heating the mixture for 16 h, it was cooled to rt and was acidified by adding 1 mL of 1N HCl. Then water was added until solids formed. The solids were collected by filtration, dissolved in 1,4-dioxane and methanol and purified by prep HPLC (method 12) to afford 3-((1R,3 aS,5aR,5bR,7aR,11aS,11bR,13 aR,13bR)-3a-((2-((1R,4R)-2,2-dioxido-2-thia-5-azabicyclo[2.2.1]heptan-5-yl)ethyl)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)bicyclo[3.1.0]hex-2-ene-6-carboxylic acid as two different isomers (isomer 1, 16.5% and isomer 2, 11.5%)

Provenance & Evidence