18473-68-2Relevant articles and documents
Geraniin, a new ellagitannin from Geranium thunbergii
Okuda,Yoshida,Nayeshiro
, p. 3721 - 3722 (1976)
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Ellagitannin Chemistry. the First Synthesis of Dehydrohexahydroxydiphenoate Esters from Oxidative Coupling of Unetherified Methyl Gallate
Quideau, Stephane,Feldman, Ken S.
, p. 8809 - 8813 (2007/10/03)
A simple o-chloranil-mediated oxidative dimerization of methyl gallate in anhydrous ether furnishes a dimethyl dehydrohexahydroxydiphenoate (DHHDP) product as a pale yellow precipitate in good yield. This methyl gallate dehydrodimer rapidly rearranges in acetone to give a mixture of two additional DHHDP regioisomers. One of these species corresponds to the isomer of the dehydro-hexahydroxydiphenoyl group commonly observed in dehydroellagitannin natural products. Sodium dithionite-mediated reduction of the initially formed dimethyl dehydrohexahydroxydiphenoate and/ or its derived regioisomers efficiently furnishes dimethyl hexahydroxydiphenoate (HHDP). Addition of N-(carbobenzyloxy)-L-cysteine benzyl ester to dimethyl dehydrohexahydroxydiphenoate(s) in THF solution produces two diastereomeric 3-S-cysteinyl derivatives of dimethyl hexahydroxydiphenoate.
Tannins and related compounds. CV. Monomeric and dimeric hydrolyzable tannins having a dehydrohexahydroxydiphenoyl group, supinanin, euphorscopin, euphorhelin and jolkianin, from Euphorbia species
Lee,Tanaka,Nonaka,Nishioka
, p. 630 - 638 (2007/10/02)
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