Dimeric Acetophenone Peroxide

Dimeric Acetone Peroxide A41-R Dimeric Acetophenone Peroxide A48-R Dime thoxyazobenzene. See Azoanisole A646-L... 

Plus 32% benzophenone + 5% dimeric benzophenone peroxide. 1 Plus 5% dimeric acetophenone peroxide. 

Even where an aldehyde is formed as a carbonyl fragment in the ozonolysis of an olefin, 1,2,4,5-tetroxans are often formed in a side reaction, depending on the solvent,131 the concentration, and the ozonization temperature. Thus dimeric acetone peroxide is obtained from isobutylene,132 dimeric benzaldehyde peroxide (129) from styrene132 and stilbene,96 132 and dimeric acetophenone peroxide (130) from a-methylstyrene.132... 

Ph3Bi(OOtBu)2 oxidizes a methyl group in diethyl ether to afford ethoxyacetic acid as the initial product [350], The peroxide also oxidizes toluene and ethylbenzene to benzaldehyde and acetophenone, respectively, via radical intermediates [343]. Thiophenol, benzophenone hydrazone, and hydrazobenzene are efficienfly oxidized by organobismufh(V) compounds [341a, c]. 2,6-Dialkylphenols are oxidatively dimerized by PhsBiCOs [300e]. 

Since the rearrangement of benzoylalkyl radicals is unrelated to the production of resinous materials (instead of the anticipated dimers) in the acetyl peroxide - alkyl phenyl ketone reactions, we must look elsewhere for an explanation. Once we come to this conclusion the fact that acetophenone is isoelec-tronic with o-methylstyrene immediately becomes significant. That is, radical additions to the carbonyl oxygen of phenyl ketones will be facilitated by resonance stabilization of the adduct, just as is the case with a-methylstyrene or styrene, i.e. 

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