O-(ALKYL- AND ARYL-OXYTHIOCARBONYL) SUGAR DERIVATIVES

Bis(1,2:5,6-di-O-isopropylidene-3-O-thiocarbonyl-α-d-glucofuranose ) disulfide (1) in pyridine undergoes a fragmentation reaction when treated with excess methyl, ethyl, propyl, or butyl alcohols, or phenol, to give the corresponding O-oxythiocarbonyl derivatives (2-6). A faster reaction and higher yield result when iodine is included in the pyridine solution. The oxythiocarbonyl compounds are stable when distilled (near 190°) under diminished pressure. Selective, acid hydrolysis of 3-O-(ethoxythiocarbonyl)-1,2:5,6-di-O-isopropylidene-α-d-glucofura nose (3 gave 3-O-(ethoxythiocarbonyl)-1,2-O-isopropylidene-α-d-glucofuranose (10), which rearranged, on standing in triethylamine, to 1,2-O-isopropylidene-α-d-glucofuranose 5,6-thionocarbonate (12). Oxidation of 3 with lead tetraacetate or silver nitrate gave the corresponding 3-O-ethoxycarbonyl derivative (8), whereas reduction of 3 with Raney nickel gave 3-O-(ethoxymethylene)-1,2:5,6-di-O-isopropylidene-α-d-glucofuranos e (11). © 1968.