Chlorine dioxide reactions with alkenes

In the reaction of chlorine dioxide with water, hypochlorous, hydrochloric and chloric acids are formed temporarily, and in alkaline solutions chlorites (C102 ), chlorates (ClOj ) and other products arise. The cation H20C1 formed in aqueous solutions of chlorine, chlorine dioxide and hypochlorites may react with alkenes and other unsaturated compounds. The electrophilic addition of HOCl to alkenes is an established reaction mechanism for a, P-chloroalcohol (chlorohydrin) and a, -dichloro derivative formation (Figure 11.16). The reaction yielding chlorohydrins follows the Markovnikov rule with the hydroxyl group adding to the more substituted carbon. Oxidation of chlorohydrins by hypochlorites... 

The reaction of chlorine in flour with unsaturated fatty acids, which are also alkenes, yields a number of fatty acid chlorinated derivatives (dichloroacids and chlorohydroxyacids). Chlorohy-droxyacids are formed preferentially with chlorine dioxide. For example, oleic acid produces 9,10-dichlorostearic, 9-chloro-lO-hydroxystearic and 10-chloro-9-hydroxystearic acids. From linoleic acid the corresponding disubstituted derivatives of oleic add or tetrasubstituted derivatives of stearic acid are formed. Their content in flour, depending on the amount of chlorine used for bleaching, is given in Table 11.14. Chlorinated fatty adds are also formed in the fat of chicken carcasses that are cooled in chlorinated water after slaughter. 

---