p-Toluenesulfonic acid → 5-(2,3,4,5-Tetramethoxy-6-methylphenyl)-5-phenylpentane-1-ol

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Reaction Steps

A 3.1 ml (5.0 mmole) of n-butyllithium.hexane solution was added dropwise to 1.51 g (5.0 mmole) of 1-benzyl-2,3,4,5-tetramethoxy-6-methylbenzene and 0.83 ml (5×1.1 mmole) of 1,1,2,2-tetramethylethylenediamine dissolved in anhydrous tetrahydrofuran (15 ml), under an atmosphere of argon at -5° C. over the period of 5 minutes, followed by stirring at -5° to 0° C. for 25 minutes. Then, a solution of 0.96 g (5.0 mmole) of 4-chlorobutanol.tetrahydropyranyl ether in tetrahydrofuran (5 ml) was added to the mixed solution over the period of 5 minutes, followed by stirring for further 15 minutes under ice-cooling. Subsequently, the cooling bath was removed, and stirring was effected at room temperature for 20 minutes. The reaction solution was cooled with ice, and made acid by adding a 10% aqueous phosphoric acid solution, and the product was extracted with isopropyl ether. The organic layer was separated out, washed with aqueous sodium chloride solution, dried (magnesium sulfate). The solvent was distilled off and the residue was dissolved in methanol (15 ml), followed by addition of 48 mg (5×1/20 mmole) of p-toluenesulfonic acid and stirring at 70° C. for 15 minutes. After cooling by standing at room temperature, the mixed solution was neutralized by adding an aqueous sodium hydrogen-carbonate solution, and the solvent was distilled off. Isopropyl ether and water were added to the residue to effect extraction. The isopropyl ether layer was washed with aqueous sodium chloride solution, dried (magnesium sulfate) and evaporated. The residual solution was chromatographed on a silica gel column to perform purification (elution with isopropyl ether) to thereby give 1.29 g (69%) of 5-(2,3,4,5-tetramethoxy-6-methylphenyl)-5-phenylpentane-1-ol. Its typical physical properties and nuclear magnetic resonance spectrum data are shown in Table 14.

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