Thio-sugars. Part 9. Derivatives of 3,6-anhydro-5-thio-D-glucose

Abstract

Pyrolysis of 3,6-anhydro-1,2-O-isopropylidene-5-O-(methylthio)thiocarbonyl-α-D-glucofuranose and of the β-L-ido-isomer gives low yields of the corresponding 5-(methylthio)carbonylthio-compounds; the main product is 2-(hydroxyacetyl)furan. The reaction of potassium thiobenzoate with 3,6-anhydro-1,2-O-isopropylidene-5-O-tosyl-α-D-glucofuranose occurs approximately ten times more rapidly than that with the β-L-ido-isomer; the products are 3,6-anhydro-5-S-benzoyl-1,2-O-isopropylidene-5-thio-β-L-idofuranose and -α-D-glucofuranose, respectively. Basic, then acid-catalysed solvolysis of the latter product, in methanol, followed by acetylation, gives methyl 2-O-acetyl-5-S-acetyl-3,6-anhydro-α- and -β-D-glucofuranoside (no pyranoside is formed), but basic solvolysis, followed by hydrolysis with trifluoroacetic acid and acetylation, gives 2-O-acetyl-1,4: 3,6-dianhydro-5-thio-α-D-glucopyranoside.