Influence of alkoxyl groups on the reactivity of benzhydrol and 1-naphthyl methyl carbinol

• Main Author: Sharan, Pandey Raghuraj
• Published: University of Surrey 1962
• Subjects: 540
• Online Access: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.751575

This thesis describes an investigation of the influence of methoxy and ethoxy groups on the tendency of benzhydrol and naphthyl ethanols to undergo alkyl-oxygen fission during their reactions. 4-Ethoxybenzhydrol, alpha-(2-methoxy-l-naphthyl)ethanol, alpha-(2-ethoxy-l-naphthyl)ethanol, and alpha-(6-ethoxy--2-naphthyl)ethanol have been obtained by reduction of the corresponding ketones, which were prepared by Friedel-Crafts reactions. Optical resolution of each alcohol has been effected by conversion into the hydrogen phthalate, followed by fractional crystallisation of appropriate alkaloidal salts. The incidence of alkyl-oxygen fission has been studied, for the hydrogen phthalate of each alcohol, by three reactions: (a) Formation of the di-benzhydryl or di-naphthyl ethyl phthalate on keeping of the hydrogen phthalate in dilute alkali. (b) Formation, by reaction with sodium-p-toluene sulphinate, of the p-tolyl sulphone. (c) Formation of the methyl ether of the alcohol, by reaction with methanol, and the course of racemization during this process. The results are discussed, and it is concluded that, for the above reactions, the promotion of alkyl-oxygen fission, by electron-release, is greater for the ethoxy than for the methoxy group, and that the relay of this electronic effect is more effective from the 2- than from the 6-position of the naphthyl nucleus.