ChemInform Abstract: Synthesis and Reactions of Regioisomeric Epoxides of the Tricyclo(4.2.2.02,5)decane Series.

ChemInform Abstract

The oxidation of the tricyclotriene (I) with peracids or with MoO₅·2 HMPA complex yields the exo-3,4-epoxide (II), the endo-7,8-epoxide (III) and/or the exo-3,4-endo-7,8-diepoxide (IV) or mixtures of these epoxides. The product distribution is governed by the nature of the oxidant and by its quantity. The exo-epoxide (II) and the endo-epoxide (III) are submitted to acidic cleavage of the epoxide moieties in order to investigate their structure-reactivity relationships. The reaction of the exo-epoxide (II) with a large excess of LiClO₄ in the presence of Ac₂O as the source of nucleophile (acetate ion), AcOH and catalytic amounts of conc. H₂SO₄ or HClO₄ yields the trans-hydroxyperchlorate (VI) and the products (VII)-(IX), which result from intramolecular cyclizations with participationof the neighboring double bond. Treatment of the endo-epoxide (III) with Ac₂O (V) in the presence of a catalytic quantity of HClO₄ gives only the product (X), which results from a Wagner-Meerwein rearrangement without participation of a double bond. Addition of LiClO₄ lowers the yield of the product (X). However, no formation of further products is observed.