Essais de Chloration Dirigée. X. Photochloration Directe D'acétates D'Alcoyles [1

Abstract

AbstractA series of alkylacetates, R–COOCH3, with R‐ = n‐propyl, isopropyl, n‐butyl, isobutyl and amyl, was chlorinated photochemically in order to obtain mono‐substituted products. Analysis of reaction samples was made by gas‐liquid chromatography and identification of monochlorinated derivatives was performed by reference synthesis and N.M.R. spectroscopy.Experimental results showed an important activation for positions of the molecules substituted by electrodonor groups like methyl. On the contrary, positions substituted by electron withdrawing functions, like the acetoxy group, were desactivated. These results were correlated by a reactivity‐structure relationship, showing the separation between inductive and resonance effects. The equation used was: magnified image with p* = ‐0.843 and h = +0.034.In view of the fact that the polar effect constants (σ*) for acetoxy and acetoxy‐methylene groups were not known, these constants were determined: magnified image.The acetoxy sigma constant was considered as the sum of two terms: inductive (σ*−1) and mesomeric (σ*+M).