Dibenzosuberone → 5-Methylene-10,11-dihydro-5H-dibenzo[a,d][7]annulene

関与物質

反応手順

Add methylmagnesium bromide (3M solution in Et2O, 48.0 mL, 144 mmol) dropwise to a cooled (0° C.) solution of dibenzosuberone (20.0 g, 96.03 mmol) in THF (140 mL) under N2 (exothermic). Let solution warm up to room temperature and continue stirring for 2 h. Cool solution to 0° C. and quench with saturated aqueous NH4Cl (exothermic, emits gas). Extract into ethyl acetate, dry organics (MgSO4) and concentrate in-vacuo. Dissolve residue in 4N HCl/dioxane (40 mL) and stir at room temperature overnight. Concentrate and dilute with H2O. Extract into ethyl acetate, dry organics (MgSO4) and concentrate to a yellow oil. Purify crude product by loading onto a 30 g plug of silica gel and eluting with hexanes until eluent shows no UV activity. Combine and concentrate hexane washes to afford 16.72 g (84%) of the title compound as a white solid, mp 65.1° C. HPLC shows 98% purity.

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