ISSN:
1434-193X
Keywords:
Electron transfer
;
Cytochrome P-450
;
α-Alkylbenzyl alcohols
;
Chemistry
;
General Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The chemical and microsomal oxidations of a number of 4-methoxy substituted α-alkylbenzyl alcohols 4-MeOPhCH(R)OH (Eox = 1.6-1.7 V vs SCE) were investigated. Using potassium 12-tungstocobalt(III)ate, a bona fide one electron oxidant, competition between Cα-H and Cα-Cβ bond cleavage in the intermediate radical cation was observed when the side-chain alkyl group R was Et (2) and iPr (3). With R = Me (1), only C-H bond cleavage took place, whereas with R = tBu (4) C-C bond cleavage was the exclusive fragmentation process. In contrast, the microsomal oxidation of the two substrates 3 and 4 led in both cases to the exclusive formation of the corresponding ketone. Thus, an electron transfer mechanism appears unlikely for the microsomal oxidation of α-alkylbenzyl alcohols, even though the oxidation potential of these species is lower than or comparable to that of the active oxidant in the enzyme. A hydrogen atom transfer mechanism is more in line with these results.
Type of Medium:
Electronic Resource
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