An efficient approach to 6-deoxy-heptose constructs has been established by one-carbon homologation of the sugar chain of hexoses. The reaction features the formation of sugar-based α-substituted propanedinitriles and ensuing diverse oxidative transformations under mild reaction conditions that are compatible with a wide range of sugars bearing various functional/protecting groups. The applications of this method are demonstrated by a divergent assembly of Campylobacter jejuni strain 81-176 capsular trisaccharide repeating unit derivatives.

An efficient protocol has been established for βglycosylations with 2-deoxy-2-(2,4-dinitrobenzenesulfonyl)amino (2dDNsNH)-glucopyranosyl/galactopyranosyl selenoglycosides using PhSeCl/AgOTf as an activating system. The reaction features highly β-selective glycosylation with a wide range of alcohol acceptors that are either sterically hindered or poorly nucleophilic. Thioglycoside-and selenoglycoside-based alcohols prove to be viable nucleophiles, opening up new opportunities for one-pot construction of oligosaccharides. The power of this approach is highlighted by the efficient assembly of tri-, hexa-, and nonasaccharides composed of β-(1 → 6)-glucosaminosyl residues based on one-pot preparation of a triglucosaminosyl thioglycoside with DNs, phthaloyl, and 2,2,2-trichloroethoxycarbonyl as the protecting groups of amino groups. These glycans are potential antigens for developing glycoconjugate vaccines against microbial infections.

Metrics & MoreArticle Recommendations W e apologize for inadvertently not making the proper citation to reductive alkylation of malononitrile with aldehydes. Three significant references corresponding to this transformation should be cited as refs 12b, 12c, and 12d in the paper and are provided as refs 1a, 1b and 1c here.These corrections do not affect any of the conclusions of the letter. The authors sincerely apologize for the inconvenience this may have caused. ■ REFERENCES(1) (a) Ramachary, D. B.; Kishor, M.; Ramakumar, K. A Novel and Green Protocol for Two-carbon Homologation: a Direct Amino Acid/K 2 CO 3 -catalyzed Four-component Reaction of Aldehydes,