Synthesis of Unnatural C-2 Amino Acid Nucleosides Using NIS-Mediated Ring Opening of 1,2-Cyclopropane Carboxylated Sugar Derivatives

We have developed a general and efficient method for the stereoselective construction of pyrimidine-based pyranosyl C-2 amino acid nucleosides using NIS-mediated ring opening of 1,2-cyclopropanated sugar derivatives. This methodology has been successfully extended to the synthesis of furanosyl nucleosides, Which have potential applications in the development of novel, nontoxic antifungal therapeutics

EFFICIENT SYNTHESIS OF O-LINKED GLYCOCONJUGATES OF AMINO ACIDS FROM CARBOHYDRATE-DERIVED DONOR-ACCEPTOR CYCLOPROPANES

N-Iodosuccinimide (NIS) mediated ring opening of carbohydrate-derived donor-acceptor cyclopropanes with free ``CO2H'' group of N-protected L-amino acids at ambient conditions afforded iodo derivatives of glycosyl ester of L-amino acids. The iodides were subsequently converted easily into corresponding azides using NaN3 in DMF followed by reduction with Zn/AcOH to produce ester linked glycosyl amino acids. A similar strategy was adopted to synthesize C-linked glycoamino acid derivatives from different N-protected L-amino alcohols. By using an orthogonal strategy C- and O-linked glycopeptides were also synthesized

Efficient synthesis of fused perhydrofuro[2,3-b]pyrans (and furans) by ring opening of 1,2-cyclopropanated sugar derivatives

An efficient method has been developed for the construction of fused perhydrofuro[2,3-b]pyrans by diastereoselective ring opening of 1,2-cyclopropanated sugar derivatives. The methodology has been successfully applied to the synthesis of fused perhydrofuro[2,3-b]pyrano-ϒ-butyrolactone derivatives