Hydrochloric Acid → HCID 18546252, compound

Participants

Reaction Conditions

Reaction Steps

A solution of 3-ethyl-7-methoxy-3-(4-methoxyphenyl)-thiochroman-4-one (13.7 g, 41.8 mmol) in anhydrous tetrahydrofuran (100 ml) was added dropwise to a solution of lithium aluminum hydride (950 mg, 25 mmol) in anhydrous tetrahydrofuran (100 ml) at −78° C. under argon atmosphere, and the resulting mixture was warmed to −20° C. over 1 hour. Ethyl acetate, methanol and 2N aqueous hydrochloric acid were added sequentially to the reaction mixture, which was then filtered through cellite. After extraction with ethyl acetate, the organic layer was washed with saturated aqueous sodium bicarbonate, water and saturated aqueous sodium chloride, and then dried over anhydrous magnesium sulfate. After distilling off the solvent, the resulting residue (13.10 g) was dissolved in 1,2-dichloroethane (360 ml) and then mixed with allyltrimethylsilane (12.47 ml, 78.75 mmol). Zinc iodide (15.08 g, 47.27 mmol) was added to this solution at 0° C. under argon atmosphere, and the resulting mixture was stirred for 4 hours at 40° C. Water and dilute hydrochloric acid were added sequentially to this mixture, which was then extracted with ethyl acetate. The organic layer was washed with saturated aqueous sodium bicarbonate, water and saturated aqueous sodium chloride, and then dried over anhydrous magnesium sulfate. After distilling off the solvent, the residue was purified by silica gel flash column chromatography (eluent: hexane/ethyl acetate=20/1) to give (3RS,4RS)-3-ethyl-7-methoxy-3-(4-methoxyphenyl)-4-(2-propenyl)thiochroman (8.73 g, Yield 62% for 2 steps).

Provenance & Evidence