1,2-O-Isopropylidene-alpha-D-xylofuranose CAS 20031-21-4

D-xylose (15.0g, 0.1mol) and anhydrous copper sulfate (34.4g, 0.216mol) were added to a 500mL round-bottomed flask, then 150mL of acetone and 3mL of 98% concentrated sulfuric acid were added, and the reaction was stirred at room temperature . The mixture was yellow-green turbid. When standing, the upper layer was a pale yellow liquid, and the lower layer was a pale blue solid. The cloudy solution gradually turned yellow-brown as the reaction proceeded. The reaction was carried out for 24 h, the mixture obtained by the reaction was filtered under reduced pressure, the filter cake was light blue, the filter cake was washed with acetone, and the filtrates were combined to obtain a yellow transparent liquid. Concentrated ammonia water was added dropwise to the filtrate to pH-7.0 to neutralize the sulfuric acid. A white flocculent precipitate (NH4)2S04 was formed. (NH4)2S04 was filtered, and the filter cake was washed with acetone to obtain a colorless liquid. Combine the filtrates, spin dry in a single-necked flask with a rotary evaporator (temperature≤50°C), and concentrate to obtain a yellow-brown syrupy substance.

100 mL of 0.1 mol·L-1 dilute hydrochloric acid was added to the diacetoneidene D-xylose obtained in the previous step, and the product was insoluble. Stirring at room temperature, the solution was gradually dissolved, and the reaction was continued for 1.5 h. TLC tracking, with CH2Cl2 developing solvent. After the reaction, solid sodium bicarbonate was added to adjust the pH to 7.2-7.5, the mixture was poured into a separatory funnel, about 30 mL of ether was added, the layers were shaken, and the organic layer was bright yellow, and the layers were separated. Repeat the wash two more times until the organic phase is colorless. Use a rotary evaporator to spin dry (temperature≤50℃), and concentrate to obtain 1,2-O-isopropylidene-α-D-xylfuranose as colorless syrup.