Dimethyl Sulfate → (4s,7r)-3-Methoxy-7,8,8-trimethyl-2-phenyl-4,5,6,7-tetrahydro-2h-4,7-methano-indazole

Participants

Reaction Steps

Dimethyl sulfate (0.4 mL, 4.1 mmol) was added to (4S,7R)-2-phenyl-7,8,8-trimethyl-1,2,4,5,6,7-hexahydro-4,7-methano-indazol-3-one (Intermediate 6; 1.00 g, 3.7 mmol) in 1 M NaOH (10 mL). The mixture was stirred at room temperature overnight and then diluted with water and extracted three times with ethyl acetate. The combined organic layers were washed with water and brine, dried (magnesium sulfate), filtered, evaporated, and purified using an Analogix Intelliflash 280 system (Analogix, Inc., Burlington, Wis.) with an RS-12 column, eluting with 0-16% ethyl acetate/hexanes to give (4S,7R)-1,7,8,8-tetramethyl-2-phenyl-1,2,4,5,6,7-hexahydro-4,7-methano-indazol-3-one (213 mg, 20%) as a white solid, (4S,7R)-3-methoxy-7,8,8-trimethyl-2-phenyl-4,5,6,7-tetrahydro-2H-4,7-methano-indazole (243 mg, 23%) as a yellow solid and unreacted starting material (243 mg, 24%).

Provenance & Evidence