Search

Benzimidazole ring system is a useful nucleus in medicinal chemistry and is found in many biologically active compounds. An efficient approach for the synthesis of 1,2-bisubstituted benzimidazoles is presented in this article, and the mechanism of the condensation from 2-[(2-aminophenylimino)phenylmethyl]-4-bromophenol, using piperdine or acetic acid as catalyst, is studied. 1,3-Shift of negative hydrogen ion is the key step for this rearrangement reaction, and the influences of catalyst, temperature, substrate, and solvent are also investigated. J. Heterocyclic Chem., 2011. [ABSTRACT FROM AUTHOR]

Full details of an enantioselective total synthesis of 8-O-4'-neolignan perseal B are presented for the first time. The synthesis was achieved in 8 steps from vanillin and involved the asymmetric dihydroxylation reaction using AD-mix-a to give the key intermedium (1S ,2S) -1-(4-(benzyloxy)-3-methoxyphenyl)propane-1,2,3-triol, and the Mitsunobu reaction between phenylpropanoid and vanillin formed perseal B. The synthetic method of perseal B exhibits a new route for 8-O-4' -neolignan. [ABSTRACT FROM AUTHOR]

convenient method for the synthesis of sesquilignan threo- and erythro-(±)-divanillyltetrahydrofuran ferulate is described. The synthesis was based on a unified synthetic strategy involving two Stobbe condensations to give the skeleton of lignan, and then reduction reaction to form meso- and threo-(±)-secoisolanciresinol. meso- and threo-(±)-secoisolanciresinol were separated by flash column chromatography, followed by intramolecular reaction with TsCl to afford the key intermediate meso- or threo-(±)-shonanin, then condensation with ferulaic acid to obtain sesquilignan threo- or its analogue erythro-(±)-divanillyltetrahydrofuran ferulate. [ABSTRACT FROM AUTHOR]