Toluene → 2-acetyl-7-benzofuranyl 2,3,4-tri-O-acetyl-5-thio-beta-D-xylopyranoside

関与物質

反応条件

反応手順

A mixture composed of 1.93 g (14.1 mM) of anhydrous zinc chloride, 1 g (5.7 mM) of 2-acetyl-7-hydroxybenzofuran and 2.2 g of molecular sieve 13× is stirred into 13 ml of toluene and 13 ml of acetonitrile. The mixture is brought to 90° C. and 1.42 g (14.1 mM) of triethylamine and 2.22 g (6.27 mM) of 2,3,4-tri-O-acetyl-5-thio-D-xylopyranosyl bromide are added, while maintaining the mixture at the temperature of 90° C. The mixture maintained at 90° C. is then stirred for 20 minutes. The mixture is subsequently cooled, 65 ml of a 0.5 N solution of sodium hydroxide are added, and the resulting mixture is stirred for one hour. The medium is filtered and the precipitate is washed with ethyl acetate. The filtrate is subsequently separated by settling out. The organic phase is washed with a saturated aqueous solution of ammonium chloride, dried over magnesium sulfate, and concentrated under reduced pressure. The evaporation residue is purified by silica gel chromatography, elution being carried out with a cyclohexane/ethyl acetate mixture (7/3; v/v). The desired product is obtained in the form of a yellowish solid with a yield of 37%.

情報源と証拠