The reaction of chlorosulfonic acid with 2-pentene in chloroform solution at 0-5” gave a mixture of isomeric pentenesulfonic acids. It was shown, by reducing the double bond of the isomers and comparing the reduced mixture with pentane-2-sulfonic acid and pentane-3- sulfonic acid, that sulfonation had occurred on the carbon atoms comprising the original position of the double bond, approximately 80% having taken place on carbon atom 2 and ...
