Boron tribromide → butyl-4,8-dimethyl-7-hydroxy-1,2,9,9a-tetrahydro-3H-fluoren-3-one

関与物質

反応手順

A solution of 9a butyl-4,8-dimethyl-7-methoxy-1,2,9,9a-tetrahydro-3H-fluoren-3-one (84 mg, 0.28 mmol) in anhydrous CH2Cl2 (3 mL) was placed under a nitrogen atmosphere, cooled in an acetone-dry ice bath, and treated with 1M BBr3 in CH2Cl2 (1.11 mL, 1.11 mmol). The cooling bath was removed and the reaction mixture was stirred at room temperature for 4 hours. The reaction mixture was diluted with EtOAc (20 mL), washed with water (20 ml) containing 2N HCl (2 mL) followed by brine (10 mL), dried over MgSO4, filtered, and evaporated under vacuum. The crude product was purified by preparative layer chromatography on a 0.1×20×20 cm silica gel GF plate, developing with 10% EtOAc in CH2Cl2. The UV visible product band was eluted with EtOAc and the solvent evaporated under vacuum. The residue was lyophilized from benzene-methanol to afford 9a butyl-4,8-dimethyl-7-hydroxy-1,2,9,9a-tetrahydro-3H-fluoren-3-one as a solid.

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