Methyl morpholine oxide → 3-(4-Isopropoxy-3-(trifluoromethyl)phenyl)-4,5-dihydronaphtho[1,2-c]isoxazole-7-carbaldehyde

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Reaction Steps

To 3-(4-isopropoxy-3-(trifluoromethyl)phenyl)-7-vinyl-4,5-dihydronaphtho[1,2-c]isoxazole (Preparation 14B, 0.18 g, 0.451 mmol) in THF (2 mL) was added N-methylmorpholine-N-oxide (50% in water) (0.093 mL, 0.451 mmol) followed by osmium tetroxide (0.071 mL, 9.01 μmol) in one portion at room temperature. The contents were stirred at room temperature for 14 h. LCMS indicated formation of a major peak corresponding to the diol intermediate. Sodium periodate (0.145 g, 0.676 mmol) dissolved in 2 mL of water was added in one portion at room temperature. The milky heterogeneous solution was stirred at room temperature for 45 min. The reaction mixture was concentrated and partitioned between ethyl acetate (15 mL) and water (10 mL). The ethyl acetate layer was dried over sodium sulfate, concentrated and purified by silica gel column chromatography (hexane/ethyl acetate) to yield 3-(4-isopropoxy-3-(trifluoromethyl)phenyl)-4,5-dihydronaphtho[1,2-c]isoxazole-7-carbaldehyde (0.06 g, 0.149 mmol, 33.2% yield) as a white solid. LC/MS M+1=402.1.

Provenance & Evidence