1,4-Dioxane--water (1/1) → 5-Isopropoxy-6-methoxy-3,4-dihydro-2H-naphthalen-1-one

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Reaction Steps

34 (120 mg, 0.55 mmol) was weighed in a 100 mL round bottom flask and a solution of 5 mL of water:dioxane (5:95) was added and the reaction was set up under nitrogen. A solution of 2,4-dichloro-5,6-dicyanobenzoquinone (0.25 g, 1.09 mmol) dissolved in 5 mL of dioxane was added dropwise to the reaction mixture. The reaction mixture was stirred for 12 h. The solid separated was filtered and washed with ethylacetate. The filtrate was concentrated under reduced pressure and 10 mL of saturated sodium bicarbonate solution was added and the resulting reaction mixture was extracted with ether (3×20 mL) and the combined organic phases dried over anhydrous sodium sulfate, filtered and evaporated in vacuo. Purification by flash column chromatography (silica gel, 30:70 EtOAc:Hexanes) yielded 90 mg (71%) of 35. Rf value: 0.458 (40:60 EtOAc:Hexanes).

Provenance & Evidence