lignans and butane

The relationship between the stereochemistry and antimicrobial activity of butane-type lignans was clarified. All stereoisomers of dihydroguaiaretic acid (DGA) showed both antibacterial and antifungal activity. The (+)- and (-)-7,7'-dioxodihydroguaiaretic acid (ODGA) also showed both antibacterial and antifungal activity, while meso-ODGA did not show antibacterial activity, but showed antifungal activity. No activity of any stereoisomer of secoisolariciresinol (SECO) was apparent.

Topics: Anti-Infective Agents; Bacteria; Butanes; Foodborne Diseases; Fungi; Guaiacol; Lignans; Plant Diseases; Stereoisomerism; Structure-Activity Relationship; Substrate Specificity

The first diastereoselective construction of butane-type and butyrolactone-type secocyclolignanes was achieved by the application of a high-valency heterobimetallic Ir-Sn complex to benzyl alcohols prepared from an Evans's anti-aldol product. The elimination of an acetoxymethyl group to give a cinnamyl structure by using a high-valency heterobimetallic Ir-Sn complex was also observed in this study.

Topics: Benzene; Butanes; Lactones; Lignans; Stereoisomerism; Substrate Specificity

[structure: see text] Full details of the asymmetric total syntheses of the dibenzocyclooctadiene lignans interiotherin A, angeloylgomisin R, gomisin O, and gomisin E (epigomisin O) are presented. The syntheses were based on a unified synthetic strategy involving a novel crotylation using the Leighton auxiliary that occurred with excellent asymmetric induction (>98:2 enantiomeric ratio), a diastereoselective hydroboration/Suzuki-Miyaura coupling reaction sequence, and an atropdiastereoselective biarylcuprate coupling, both of which occurred with total (>20:1) stereocontrol. The syntheses were achieved in six to eight steps from simple aromatic precursors.

Topics: Aldehydes; Biological Products; Boric Acids; Butanes; Cyclooctanes; Hydrogen; Lignans; Methylation; Molecular Structure; Oxidation-Reduction; Stereoisomerism