Studies on the reactivity of (pentitol-1-yl)nitrocyclohexadienes with acetyl chloride in methanol

Abstract

(Pentitol-1-yl)nitrocyclohexadienes with pentaacetylated d- galacto and d- manno sugar side-chains react in different ways when they are subjected to transesterification with acetyl chloride in methanol. Although both processes should commence with a deacetylation, subsequent intramolecular nucleophilic attack from the resulting hydroxyl groups on electrophilic carbons on the cyclohexadiene ring was dependant on the nature of the sugar side-chain, as well as on the configuration at the stereogenic carbon of the cyclohexadiene ring. Thus, d- manno nitrocyclohexadiene led to a complex mixture from which we could either isolate or identify products with dioxatricyclodecane dimethyl ketal, benzofuran, chromane-3,4-diol, bicyclic or tricyclic oximes, nitrobenzene, and nitrocyclohexenol structures. In contrast, d- galacto nitrocyclohexadiene led exclusively to a bicyclic oxime.