CCCXXII.—The conditions underlying the formation of unsaturated and cyclic compounds from halogenated open-chain derivatives. Part V. Products derived from α-halogenated β-methylglutaric acids

Christopher Kelk Ingold
1922 Journal of the Chemical Society Transactions  
IN Part I of this serics (T., 1921,119, 305), the suggestion was made that the anglc between any two valencies of a carbon atom is determined by the atomic volumes of the four groups attached. From this hypothesis it followed that the carbon valencies of an unstrairicd polymethylene chain are inclined, not a t 109.5" as Baeyer's theory requires, but 115.3", and a means was thus found of accounting for the small tendency to the formation of cyclobutane rings, the similar stability of
more » ... lity of cgclopentane and cyclohexane rings, and the marked effect of two alkyl groups attached to the same carbon atom in promoting the formation of three-, four-, and five-membered homocyclic rings. It is proposed now to examine the effect of a single alkyl group on the ease of closure of these rings. Adopting the method of calculation previously employed, it is seen that a carbon atom attached t o three carbon atoms and one hydrogen atom is t o be represented by an irregular tetrahedron having three planes of symmetry : 7 s (cosec 0 -zd3 cot Z+ -1) + d = (--2 sin 0 = &?sin 2+ 43 + 2~f z j f + z;t)l and of which the solution for 8 is d -+ 2/3d coscc 8 = 1 -k __ %' "(")' --3 -2 v L' s--3 V 3 This equation leads to the value 28 = 112.5', that is, slightly more than the arithmetic mean between the values of the comes-
doi:10.1039/ct9222102676 fatcat:7avrt45uzzfdxfogrlls5f4awe