Alcohols exchange phenomena

Why is the exchange phenomenon limited to primary alcohols and is there an electronic effect separate from the steric effect ... 

Vardanyan [65,66] discovered the phenomenon of CL in the reaction of peroxyl radicals with the aminyl radical. In the process of liquid-phase oxidation, CL results from the disproportionation reactions of primary and secondary peroxyl radicals, giving rise to trip-let-excited carbonyl compounds (see Chapter 2). The addition of an inhibitor reduces the concentration of peroxyl radicals and, hence, the rate of R02 disproportionation and the intensity of CL. As the inhibitor is consumed in the oxidized hydrocarbon the initial level of CL is recovered. On the other hand, the addition of primary and secondary aromatic amines to chlorobenzene containing some amounts of alcohols, esters, ethers, or water enhances the CL by 1.5 to 7 times [66]. This effect is probably due to the reaction of peroxyl radicals with the aminyl radical, since the addition of phenol to the reaction mixture under these conditions must extinguish CL. Indeed, the fast exchange reaction... 

Cookson has studied substrates that can, in principle, effect a tandem Claisen-Cope-Cope rearrangement. By employing 1,1,3-trimethoxybutane as a surrogate for 1-methoxy-1,3-butadiene (equation 10), allylic alcohol (62) undergoes acid-catalyzed exchange to provide the transient p,y-unsaturated aldehyde (66) which, lacking a substituent at the a-position, suffers a facile conjugation of the double bond that preempts the tandem process. This phenomenon has been also observed by Thomas. ... 

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