Abstraction, multiple reaction paths

Multiple reaction paths can arise from symmetry. Let s take some time to consider one example in detail. Consider again the energy profile of Fig. 7 along a reaction path for the abstraction reaction [52, 53] (with Dj rather than H2)... 

Figure 15. Integrated scheme for lipid oxidation accounting for multiple reactions pathways competing with the classic hydrogen abstraction. Dotted lines indicate paths for oxygen addition to secondary radicals formed in cyclic and addition products, with formation of new peroxyl radicals.

This is in conflict with the observation [41] that basic oxide surfaces tend to totally oxidize the alcohol (multiple proton abstraction) and that acidic oxides exhibit a correlation between acidity and formaldehyde production. On suitably acidic surfaces the reaction mechanism may be dominated by the electrophilic action of protons on the methanol leading to an embedded methoxy which is easily activated at the methyl positions. On HPA catalysts this reaction path was claimed to be dominating [27] as long as the catalyst was sufficiently acidic. For the... 

---