1,2-Dichloroethane → (E)-3-((3aS,5aR,5bR,7aR,9S,11aR,11bR,13aS)-9-((4-(Tert-butoxy)-3,3-dimethyl-4-oxobutanoyl)oxy)-1-isopropyl-5a,5b,8,8,11a-pentamethyl-2-oxo-3,3a,4,5,5a,5b,6,7,7a,8,9,10,11,11a,11b,12,13,13a-octadecahydro-2H-cyclopenta[a]chrysen-3a-yl)acrylic acid

Participants

Reaction Conditions

Reaction Steps

To a solution of 4-(tert-butoxy)-3,3-dimethyl-4-oxobutanoic acid (122 mg, 0.604 mmol), DMAP (123 mg, 1.007 mmol) and EDC (193 mg, 1.007 mmol) in dichloromethane (12 mL) stirred at room temp for 30 min was added (E)-3-((3aS,5aR,5bR,7aR,9S,11aR,11bR,13aS)-9-hydroxy-1-isopropyl-5a,5b,8,8,11a-pentamethyl-2-oxo-3,3a,4,5,5a,5b,6,7,7a,8,9,10,11,11a,11b,12,13,13a-octadecahydro-2H-cyclopenta[a]chrysen-3a-yl)acrylic acid (100 mg, 0.201 mmol). The reaction mixture was stirred at 25° C. for 3 h. The produce was extracted with DCM (15 mL*3), the combined organic phase was washed with brine (20 mL), dried, and the solvent removed under reduced pressure to give 110 mg of residue as light yellow solid which was used in the next reaction without further purification.

Provenance & Evidence