Sodium cyanoborohydride → (3aR,5aR,5bR,7aR,9S,11aR,11bR,13aS)-3a-(2-((1-(5-chloropyrimidin-2-yl)cyclopropyl)amino)-1-hydroxyethyl)-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-9-yl acetate

Participants

Reaction Steps

To a solution of (3aR,5aR,5bR,7aR,9S,11aR,11bR,13aS)-3a-(1-hydroxy-2-oxoethyl)-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-9-yl acetate (104) (545 mg, 1.035 mmol) and 1-(5-chloropyrimidin-2-yl)cyclopropanamine, hydrochloride (105) (213 mg, 1.035 mmol) in methanol (5 ml) and 1,2-dichloroethane (5 ml) was added zinc chloride (141 mg, 1.035 mmol). The reaction mixture was stirred at room temperature overnight. and then sodium cyanoborohydride (65.0 mg, 1.035 mmol) was added. The reaction mixture was allowed to stir for 1 h, then silica gel was added to the mixture and the solvents removed in vacuo to give the residue-silica gel powder which was purified on a silica gel column using petroleum ether/EtOAc (5:1 to 3:1) to afford (3aR,5aR,5bR,7aR,9S,11aR,11bR,13aS)-3a-(2-((1-(5-chloropyrimidin-2-yl)cyclopropyl)amino)-1-hydroxyethyl)-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-9-yl acetate (105) as a mixture of diastereomers (200 mg, 0.166 mmol, 16.04% yield) as a yellow foam. LC/MS: m/z calculated 679.4. found 680.3 (M+1)+.

Provenance & Evidence