5017-36-7Relevant academic research and scientific papers
Opening of the Cyclopropane Ring of the Thujan-3-ols in Fluorosulphuric Acid
Rees, John C.,Whittaker, David
, p. 953 - 957 (1981)
The reactions of the isomeric thujan-3-ols with fluorosulphuric acid to give 2,3-dimethyl-4-isopropylcyclopentenium ion have been investigated.The initial ring opening involves at least two mechanisms yielding a carbocation and an olefin.Subsequent reaction, possibly by elimination and olefin shift, gives the 2,3-dimethyl-4-isopropylcyclopent-2-enol, which rapidly ionises to the observed ion.The reaction has been studied by means of deuterium tracers, in the solvent and in the substrate, and by comparison of the reaction with those of related substrates.
Citronellal cyclisation in superacids
Dean, Christopher,Whittaker, David
, p. 1275 - 1277 (2007/10/02)
The cyclisation of citronellal in superacids parallels closely the reaction in 'normal' acids, yielding isopulegol and neoisopulegol. Each alcohol then undergoes protonation at the double bond; neoisopulegol loses water to give 2-(4-methylcyclohex-1-en-1-yl)prop-2-yl cation, but in isopulegol this process is stereochemically unfavourable, and competes with a 1,5-hydride shift to yield the 1-methyl-4-isopropyl cyclohexenyl cation. Hydroxycitronellal yields only the 2-(4-methylcyclohex-1-en-1-yl)prop-2-yl cation by an unknown route.
