112371-50-3Relevant articles and documents
Oxymetallation. Part 23. Peroxymercuriation of Bicycloalkanes
Bloodworth, A. J.,Chan, Kam Hung,Cooksey, Christopher J.,Hargreaves, Neville
, p. 1923 - 1930 (2007/10/02)
The peroxymercuriations of bicycloalkanes, n = 2-4, have been carried out using mercury(II)acetate and a one-fold excess of t-butyl hydroperoxide in dichloromethane with 20 molpercent of perchloric acid as catalyst, the products being isolated, after anion exchange, as the organomercury(II)bromides.Small amounts of acetoxymercurials are also formed but are easily removed by silica chromatography.Bicyclopentane reacts by exclusive cleavage of the zero-bridge to give cis-1-bromo-mercurio-3-t-butylperoxycyclopentane 4, but competing isomerisation to cyclopentene consumes ca. 50percent of the cyclopropane.Reaction in neat t-butyl hydroperoxide without perchloric acid gives only the peroxymercurial 4.This has been converted into 2,3-dioxabicycloheptane 2a by iododemercuriation then reaction with silver trifluoroacetate.Bicycloheptane reacts by exclusive cleavage of the one-bridge to give cis- and trans-1-bromomercuriomethyl-2-t-butylperoxycyclohexanes 28 and 29, which have been reduced with alkaline sodium borohydride to afford the corresponding 1-methyl compounds 32 and 33.Bicyclohexane reacts by both zero-bridge and one-bridge cleavage to give the γ-peroxymercurials trans-1-bromomercuriomethyl-2-t-butylperoxycyclopentane 10 and 1-bromomercurio-3-t-butylperoxycyclohexane 13.Also formed is a similar amount of the isomeric β-peroxymercurials 1-bromomercuriomethyl-1-t-butylperoxycyclopentane 11 and trans-1-bromomercurio-2-t-butylperoxycyclohexane 14 yet neither starting cyclopropane nor product γ-peroxymercurial is isomerised by perchloric acid.These unusual rearrangements are also obtained with n-butyl hydroperoxide but not with methanol, butanol or acetic acid as nucleophile.They do not take place with other strong acid catalysts, and are inhibited by 2,6-di-t-butyl-4-methylphenol and promoted by di-t-butyl peroxyoxalate.Reaction in neat t-butyl hydroperoxide at 60 deg C without perchloric acid gives only the γ-peroxymercurials 10 and cis-13.Iododemercuriation of the cis-1,3-cyclohexane derivative cis-13. then reaction with silver trifluoroacetate, gives mainly 3-t-butoxycyclohexanone 27 rather than 6,7-dioxabicyclooctane.
