Hydroacetoxylation of Polycyclic Cyclopropane-Containing Hydrocarbons with Ethylidene Diacetate and Dimethyl Carbonate in the Presence of Ionic Liquid [Et3NH]+ [HSO4]–

Abstract

Hydroacetoxylation of a series of strained polycyclic cyclopropane-containing hydrocarbons, namely four stereoisomeric hexacyclic norbornadiene dimers (exo,exo-, exo,endo-, endo,exo-, and endo,endohexacyclo[9.2.1.0^2,10.0^3,8.0^4,6.0^5,9]tetradecanes) and heptacyclic binor-S, in the presence of the ionic liquid [Et₃NH]⁺ [HSO₄]⁻ has been performed for the first time. Both ethylidene diacetate and dimethyl carbonate have been shown to act as an effective source of acetoxy group. The reaction selectively involves cleavage of the most strained C⁴–C⁵ bond of the cyclopropane ring, leading to the formation of the corresponding exo-acetoxy derivatives in up to 85% yield. The effects of temperature, reaction time, and reactant ratio on the yield have been studied. The described reactions provide a preparatively convenient synthetic approach to acetoxy derivatives of polycyclic cage hydrocarbons that are promising as intermediate products for the synthesis of biologically active compounds and functional materials.