Studies in the synthesis of some hydrocarbons

Abstract

This work was begun with the object of investigating an anomalous result obtained by Dr. M.S. Lesslie of Bedford College when she attempted to prepare 2:7-dimethyloctane by the following method. The Grignard reaction gave the desired 2:7-dimethyloctan-2:7-diol but the distillation of this compound with naphthalene-2-sulphonic acid did not give the expected 2:7-dimethylocta-2:6-diene. An unsaturated compound was obtained which on hydrogenation in glacial acetic acid in the presence of Adams's platinum catalyst gave a saturated substance which was distilled and gave the following fractions:-Fractions (3) and (4) were combined. Found: C, 85.4;H, 14.3. C10H20 requires C, 85.6; H, 14.4%.The infra-red spectrum (determined by Dr. Beaven at the Thornton Research Centre), high refractive index, and analysis, were consistent with the supposition that this compound was 1:1:2:2-tetramethylcyclohexane.In attempts to prepare 1:1:2:2-tetramethyl-cyclohexane, Dr. Lesslie treated 2:7-dibromo-2:7-dimethyl-octane with magnesium, sodium, lithium, and lithium phenyl, but none of these experiments gave a product whose physical constants corresponded with those of the supposed tetramethylcyclohexane. The substances which were obtained were not investigated further. It was at this stage that the work described in Part I of this thesis was begun with the object of synthesizing 1:1:2:2-tetramethylcyclohexane and thus either confirming or disproving the postulated structure of the hydrocarbon obtained from 2:7-dimethyloctan-2:7-diol.