Mäkelä T H, Kaltia S A, Wähälä K T, Hase T A
Organic Chemistry Laboratory, Department of Chemistry, P.O. Box 55 (A.I. Virtasen aukio 1), FIN-00014 University of Helsinki, Finland.
Steroids. 2001 Oct;66(10):777-84. doi: 10.1016/s0039-128x(01)00107-6.
Two trans-alpha,beta-dibenzyl-gamma-butyrolactone lignans carrying a hydroxyl group at the beta-benzylic carbon atom and a alpha-hydroxy alpha,beta-dibenzyl-gamma-butyrolactone lignan were synthesized in racemic form using the tandem conjugate addition reaction to construct the basic lignan skeleton. Subsequent reaction steps involved either a catalytic reduction of the regenerated keto group to the alcohol, or a hydrogenolysis to benzylic methylene followed by lactone enolate formation and oxidation to give the alpha-hydroxybutyrolactones. These procedures were applied for the synthesis of 7'-hydroxyenterolactones and 7'-hydroxymatairesinols, and 8-hydroxyenterolactones, respectively. The diastereomeric mixtures of these compounds were separated either by HPLC techniques or column chromatography and the structures were elucidated using NMR spectroscopy.
