Synthesis of 1,2,3-Triazoles Bearing a 4-Hydroxyisoxazolidine Moiety from 4,5-Unsubstituted 2,3-Dihydroisoxazoles

Article abstract of DOI:10.1002/ejoc.202000737

A synthetic approach towards new 1,2,3-triazoles bearing the 3-hydroxymethylated 4-hydroxyisoxazolidine moiety has been described. The strategy has relied on dihydroxylation and epoxidation reactions of 4,5-unsubstituted 2,3-dihydroisoxazoles, allowing the introduction of the hydroxy group at the isoxazolidine ring in a trans stereoselective manner with respect to the substituent at C-3 carbon atom. The requisite 5-azidoisoxazolidines have been prepared from activated isoxazolidines possessing a good leaving group at C-5 carbon atom by treatment with trimethylsilyl azide and Lewis acid (isoxazolidinyl benzoates) or with sodium azide (chloroisoxazolidines). The 1,2,3-triazole moiety has been synthesized through copper(I)-catalyzed azide-alkyne cycloaddition.