Studies of cyclic hydrocarbons

Abstract

This thesis is presented in three sections.Section I deals with the synthesis of spiro-hydrocarbons.The two compounds spiro(5:2)octane and spiro(4:2)heptane were prepared; the latter compound has not previously been described. It was not found possible to synthesise a series of spiro-compounds containing varying numbers of cyclobutane rings, because of the failure to isolate pure intermediate products.Section II describes the formation of o-xylene through 4:5-dime thylenecyolohexene. The scheme to prepare this cyclohexene involved the Hofmann degradation of the quaternary ammonium hydroxide derived from cis-4:5-bis(dimethylamino-methyl)cyolohexene dimethiodide, 4:5-Dimethylenecyclohexene was not isolated, but a sample of o-xylene was obtained which was identified by the preparation of its sulphonamide.Seotion III is subdivided into three parts. Part 1 deals with the study of the anomalous reductions of 2:2'-diacetyldiphenyl under different conditions. The reductions were carried out in an attempt to devise a scheme for the preparation of 2:2'-dialkyldiphenyls. The Clemmensen reduction yielded 9:10-dimethylphenanthrene; the products isolated from the Huang Minion reduction on the same diketone were an unsaturated hydrocarbon and 9:10-dimethylphenanthrene. The course of this reaction is studied in detail.No pure compounds were isolated from the product of the Meerwein-Ponndorf-Verley reaction, but the reduction with lithium aluminium hydride gave the expected carbinol. Part 2 is devoted to the condensation reactions of 2:2'-bis(bromomethyl)dipheryl with 1:1:2:2-tetracarbethoxyethane, 1:1:3:3-tetracarbethoxypropane, and diethyl methylmalonate. The reaction with 1:1:3:3-tetracarbethoxypropane and the dibromide produced a compound which was not identified, but possible structures are proposed. The condensation reaction with diethyl mathylmalonate gave the expected product, which led to the preparation of several new compounds.Part 3 describes several methods of preparation of 2:2'-diphenyl diacetic acid, which is considered to be a suitable starting compound in the syntheses of some large-membered ring compounds of diphenyl.