ABSTRACT
Nitro sugars are considered important synthetic intermediates in glycochemistry. Nitro alcohols 2a and 2b have been recently used as key starting materials for the synthesis of carbopeptoids and their triazole isosters. Diastereoisomeric mixture 2a,b can be easily dehydrated by the use of Moffatt protocol and the obtained a,ß-unsaturated nitromethylene derivative is susceptible to Michael additions with various nucleophiles. Combination of the latter sequence with isoxazole formation in a 1,3-dipolar cycloaddition reaction opens possibilities for the synthesis of various synthetic glycoconjugates. The choice of the base, solvent, concentration, and reaction temperature showed major influence on reaction diastereoselectivity. The reaction was performed in open beakers without protecting atmosphere using commercially available reagents and solvents. Chemical shifts values are reported in ppm. The residual non-deuterated solvent peaks were used as the internal reference.
