Potassium Permanganate → Ethyl 6'-bromo-1'-(1,1-dimethylethylsulfinamido)-4-methoxy-1',3'-dihydrospiro[cyclohexane-1,2'-indene]-1'-carboxylate

Participants

Reaction Steps

To a solution of N-(6′-bromo-1′-(1-ethoxyvinyl)-4-methoxy-1′,3′-dihydrospiro[cyclohexane-1,2′-indene]-1′-yl)-2-methylpropane-2-sulfinamide (5) (200 mg, 0.48 mmol) in acetone (15 mL) at room temperature (23° C.) was added a KMnO4 solution (5.8 mL, prepared by dissolving 9.5 g of KMnO4 in 100 mL of H2O). The mixture was stirred room temperature for 16 h. Another portion of KMnO4 solution (2.2 mL) was added and stirred another 12 h. The reaction was quenched with 5% NaHSO3, stirring until colorless clear solution achieved before combined. The combined organic phases were extracted with EA 2 times, washed with brine, dried over Na2SO4, evaporated after filtration. The residue was purified by flash chromatography on silica gel eluted with EA in hexane (0-60%) to afford the desired amino ester (6) (62.8 mg, 31%). MS ESI+ve m/z 486 (M+H)+.

Provenance & Evidence