Epimine nucleophilic cleavage

Most epimino sugars are relatively stable in neutral or basic conditions. They are usually stable in the presence of such hydride reductive reagents as lithium aluminum hydride or sodium borohydride. They tend to undergo cleavage reactions or decompose in the presence of acids. A-Acylated aziridines are prone to lose the A -acyl substituent in the presence of nucleophiles and bases, and caution must be taken when nucleophilic cleavage of the aziridine ring of N-acylated epimines is to be performed. 

Hashimoto and coworkers published two papers dealing with nucleophilic cleavage of hexopyranoside-derived epimines. In the first one," the cleavage of... 

Cleavage of the A-benzyl-, A-o-nitrobenzenesulfonyl, and A-tosyl-2,3-D-a//o-epimines 160, 195, and 288, with nucleophiles (azide anion and HBr) proceeds according to the Fiirst-Plattner rule and only diaxial isomers are formed. 

Epimines of the u-galacto, D-allo, and D-talo configurations have been treated with analogous nucleophiles as for the 2,3-epimines, and their cleavage reactions are summarized in Tables XII, XIII, and XIV. 

Dauban and coworkers published a detailed study on the reactivity of 2,3-epimino-2,3-dideoxy-D-lyxono-1,4-lactone derivatives 370, 380 with both soft (RSH, AcOH, LiBr) and hard (ROH, BnNH2) nucleophiles. Reactions of the epimines with soft nucleophiles proceeded by direct aziridine-ring cleavage to give predominantly C-2 regioisomers. 

In a series of papers,Saeki and coworkers described cleavage reactions by nucleophiles of 5,6-epimines derived from hexofuranosides or hexo-furanoses, and 6,7-epimines derived from heptopyranoses. 

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