Publication at Faculty of Science |
2009
Abstract
1,6-Anhydro-2,3,4-trideoxy-2,3-(tosylepimino)-beta-D-hexopyranoses 1 and 2 underwent aziridine ring-opening reactions with halides and other heteroatom-centered nucleophiles. Ribo-epimine 1 provided trans-diaxial and cis products.
The lyxo-epimine 2 gave trans-diaxial and trans-diequatorial products, depending upon the reaction conditions (acid cleavage versus base cleavage) and the nucleophile (hard nucleophiles versus soft ones). These results have been rationalized by assuming that both S(N)2 and borderline S(N)2 cleavage mechanisms are operative.