1,4-Dioxane → 2a-(3-Formylpropyl)-2a,3,4,5-tetrahydro-1H-benz[cd]indol-2-one

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Reaction Steps

In a shaded container, 2a-(4-pentenyl)-2a,3,4,5-tetrahydrobenz[cd]indole-2(1H)-one (1.3 g, 5.3 mmol) and N-methylmorpholine oxide (1.9 g, 16 mmol) were dissolved in a mixed solvent of 1,4-dioxane (20 ml) and water (10 ml), and the resulting solution was mixed with osmium tetroxide (4% aqueous solution 3.4 ml, 0.53 mmol) and stirred at a room temperature for 2 hours. The reaction solution was mixed with water (80 ml), and then the reaction product was extracted with ethyl acetate, washed with saturated brine and dried with anhydrous sodium sulfate. Then the solvent was evaporated under a reduced pressure. The thus obtained residue was dissolved in a mixed solvent of 1,4-dioxane (20 ml) and water (10 ml). The resulting solution was mixed with sodium periodate (2.6 g, 12 mmol) and stirred for 2.5 hours as such. Water (100 ml) was added to the reaction solution, and the reaction product was extracted with ethyl acetate, washed with saturated brine and dried with anhydrous sodium sulfate. By evaporating the solvent from the resulting extract under a reduced pressure, 1.3 g of the title compound was obtained (5.3 mmol, 100% in yield).

Provenance & Evidence