Potassium Permanganate → Spiro[cyclopropane-1,1'-[1H]inden]-3'(2'H)-one, 6'-bromo-

Participants

Reaction Steps

To a solution of 6′-bromo-2′,3′-dihydrospiro[cyclopropane-1,1′-indene] (5.7 g, 25.6 mmol) in acetone (78 mL) and 1.5 M aq. MgSO4 (29 mL) was added KMnO4 (4.46 g, 28.2 mmol). The reaction was stirred overnight at room temperature. Upon completion, the reaction was filtered over celite and concentrated. The residue was partitioned between water (100 mL) and EtOAc (200 mL), and the layers were separated. The organic was washed with brine, dried over Na2SO4, then filtered and concentrated. 6′-bromospiro[cyclopropane-1,1′-inden]-3′(2′H)-one (2.11 g, 39% yield) was isolated as a white solid after flash chromatography over silica gel (5% EtOAc/hexane eluent). 1H NMR (400 MHz, CHLOROFORM-d) δ ppm 7.59 (d, J=8.3 Hz, 1H), 7.45 (dd, J=8.0, 1.5 Hz, 1H), 7.14 (d, J=1.3 Hz, 1H), 2.76 (s, 2H), 1.15-1.34 (m, 4H); MS (EI) m/z=238.1 [M+1]+.

Provenance & Evidence