300346-48-9Relevant academic research and scientific papers
Selective protection of catechin gives access to the intrinsic reactivity of the two phenol rings during H-abstraction and photo-oxidation
Cren-Olivé, Cécile,Lebrun, Stéphane,Hapiot, Philippe,Pinson, Jean,Rolando, Christian
, p. 5847 - 5851 (2000)
Selective protection of the catechol ring of catechin has been achieved. From this key compound, catechin analogues protected either on the catechol or the resorcinol rings were synthesized. From these analogues, phenoxyl radicals on the catechol or on the resorcinol rings were produced by photo- oxidation (direct irradiation at 308 nm) of the phenolate and by H- abstraction experiments. Spectra of the radicals were recorded at short times before any further chemical evolution. Investigation of catechin behavior itself and comparison with the reactivity of models show that H-abstraction is unselective, whereas photo-oxidation is selective on the catechol ring monoanion establishing that this ring has the lowest pKa. (C) 2000 Elsevier Science Ltd.
An efficient synthesis of the four mono methylated isomers of (+)-catechin including the major metabolites and of some dimethylated and trimethylated analogues through selective protection of the catechol ring
Cren-Olive, Cecile,Lebrun, Stephane,Rolando, Christian
, p. 821 - 830 (2007/10/03)
The four monomethylated isomers of (+)-catechin in positions 3′, 4′, 5 and 7, two dimethylated derivatives, the 5,7-dimethylcatechin and the 3′, 4′-dimethylcatechin and two trimethylated isomers of (+)-catechin in positions 3′, 5, 7 and 4′, 5, 7 were synthesized by a new method based on successive and selective protections of the various phenol functions present on (+)-catechin. The key step was the selective protection of the catechol ring with dichlorodiphenylmethane and di-tert-butyldichlorosilane.
