Oxymetallation. Part 13. Synthesis of bicyclic peroxides via peroxymercuriation of cyclic dienes

Abstract

The bis-mercuriated derivative (12) of 9,10-dioxabicyclo[3.3.2]decane has been prepared by peroxymercuriation of cis,cis-cyclo-octa-1,5-diene, but substantial amounts of bicyclic ethers are also formed in the reaction. The bicyclic peroxides (4) and (5) have been obtained from (12) by reduction and brominolysis respectively. 8,9-Dioxabicyclo[5.2.1]decane (6) and the dibromo-derivative (7) have similarly been prepared by peroxymercuriation and demercuriation of cyclo-octa-1,4-diene. It is suggested that the isomeric purity of the peroxides and the concurrent formation of bicyclic ethers both result from equilibrium control of reversible (per)oxymercuriation–de(per)oxymercuriation. A low yield of the [3.2.1]-peroxide (8) has been obtained by peroxymercuriation and brominolysis of cyclohexa-1,4-diene, but attempts to prepare [2.2.1]-compounds from 5,5-disubstituted cyclopentadienes have been unsuccessful.