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Cis-trans Isomerization of silybins A and B.

ABSTRACT: Methods were developed and optimized for the preparation of the 2,3-cis- and the 10,11-cis-isomers of silybin by the Lewis acid catalyzed (BF3?OEt2) isomerization of silybins A (1a) and B (1b) (trans-isomers). The absolute configuration of all optically pure compounds was determined by using NMR and comparing their electronic circular dichroism data with model compounds of known absolute configurations. Mechanisms for cis-trans-isomerization of silybin are proposed and supported by quantum mechanical calculations.

SUBMITTER: Novotna M

PROVIDER: S-EPMC4077359 | biostudies-literature | 2014

REPOSITORIES: biostudies-literature

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cis-trans Isomerization of silybins A and B.

Novotná Michaela M Gažák Radek R Biedermann David D Di Meo Florent F Marhol Petr P Kuzma Marek M Bednárová Lucie L Fuksová Kateřina K Trouillas Patrick P Křen Vladimír V

Beilstein journal of organic chemistry 20140508

Methods were developed and optimized for the preparation of the 2,3-cis- and the 10,11-cis-isomers of silybin by the Lewis acid catalyzed (BF3∙OEt2) isomerization of silybins A (1a) and B (1b) (trans-isomers). The absolute configuration of all optically pure compounds was determined by using NMR and comparing their electronic circular dichroism data with model compounds of known absolute configurations. Mechanisms for cis-trans-isomerization of silybin are proposed and supported by quantum mecha ...[more]

PMID: 24991256

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