Phosphoric Acid → Diacetone-D-glucose

Participants

Reaction Steps

Anhydrous D-glucose (600w), dry acetone (4000v), anhydrous pulverized zinc chloride (480w) and 89% O-phosphoric acid (30v) and anhydrous copper sulphate (100w) were mechanically stirred for 30 hours at room temperature. Undissolved glucose was filtered and washed with acetone. The filtrate was cooled to 0°-5° C., made alkaline with sodium hydroxide (340w in 340w water) and filtered. The filtrate was evaporated under reduced pressure to remove solvent, the residue diluted with water and extracted with chloroform. The combined chloroform extract was washed with water, concentrated, dried and evaporated to give crude product (462w, 91% on recovered glucose), white crystals, mp 95°-101° C. Recrystallization from hexane/chloroform (2;1) afforded 1,2: 5,6-di-O-isopropylidene-α-D-glucofuranose, mp 105°-109° C.

Provenance & Evidence