Water → HCID 18325103, compound

Participants

Reaction Steps

Butyl lithium (1.6M hexane solution: 36 ml) was added dropwise to a solution of helioalcohol (4.0 g) in benzene (100 ml) at room temperature. The mixture was stirred at room temperature for one hour, followed by addition of 4-methoxybenzonitrile (3.85 g) in benzene (20 ml). The mixture was stirred at room temperature overnight, followed by addition of water and extraction with ether. The organic layer was washed with water, dried over magnesium sulfate and concentrated under reduced pressure. The residue was dissolved in toluene (75 ml), followed by addition of dimethyl fumarate (7.58 g) and trichloroacetic acid (0.3 g). The mixture was refluxed for 3 hours and concentrated under reduced pressure. The reside was dissolved in ethyl acetate and washed with water, an aqueous saturated sodium hydrogen carbonate solution and brine, dried over magnesium sulfate and concentrated under reduced pressure. The residue was purified with silica gel column chromatography (silica gel: 50 g. eluent:ethyl acetate−hexane=1:2) to yield tetrahydro-2,4-epoxynaphthalene derivative (2.84 g) as a mixture of diastereoisomers. This was dissolved in a mixture of THF (5 ml) and methanol (5 ml), followed by addition of an aqueous NaOH (1.1 g) solution (5 ml). The mixture was stirred overnight and concentrated under reduced pressure. After being diluted with water, the mixture was washed with ethyl acetate. Conc. HCl was added to the aqueous layer until its pH becomes about 2.The mixture was extracted with ethyl acetate. The extract was washed with brine, dried over magnesium sulfate and concentrated under reduced pressure. The residue was dissolved in ether (50 ml), followed by addition of conc. HCl. The mixture was refluxed for 10 minutes and concentrated under reduced pressure, followed by addition of water. The resulting precipitate was collected by filtration and washed with methanol and ether to yield the title compound (2.64 g).

Provenance & Evidence