Preparation of 2-C- and 3-C-cyano-2-enopyranoside derivatives and their epoxidation

Methyl 4,6-O-benzylidene-2-C- and 3-C-cyano-2,3-dideoxy-D-erythro-hex-2-enopyranosides and -2-enitols were prepared and their epoxidation was performed.

Synthesis of the methyl alpha-glycosides of some isomalto-oligosaccharides specifically deoxygenated at position C-3

Methyl alpha-isomaltoside and methyl alpha-isomaltotrioside specifically deoxygenated at position C-3 of various glucopyranosyl units were synthesized by condensation of either 1,6-di-O-acetyl-2,4-di-O-benzyl-3-deoxy-alpha,beta-D-ribo-hexopyranos e (7) or 1,6-di-O-acetyl-2,3,4-tri-O-benzyl-alpha,beta-D-glucopyranose [mediated by silver perchlorate and tin(IV) chloride] with suitably blocked derivatives of methyl alpha-D-glucopyranoside, its 3-deoxy analog (6), or methyl 3'-deoxy alpha-isomaltoside (10), respectively.

Synthesis of stereospecifically labeled 3,6-dideoxyhexoses

Preparations of ascarylose (3,6-dideoxy-L-arabino-hexose), abequose (3,6-dideoxy-D-xylo-hexose), and paratose (3,6-dideoxy-D-ribo-hexose) with stereospecific deuterium labeling at C-3 are discussed. The methods used to synthesize these sugars, such as the hydrogenation of olefins, the displacement of halides, the reduction of epoxides, and the substitution of tosyl esters, illustrate a variety of strategies leading to stereospecific deuterium incorporation. Many of the techniques described here should be of general utility for the synthesis of other deuterium-labeled sugars.