Preparation of menisdaurigenin and related compounds.

Menisdaurin (1), a cyano glucoside, was first isolated in 1978 from Menispermum dauricum (Menispermaceae) and named after the plant. It has been also isolated from several plant sources. The stereochemistry of the aglycone part was first reported as (Z,4R,6S)-enantiomer of (4,6-dihydroxy-2-cyclohexen-1-ylidene)acetonitrile based on the CD spectrum of menisdaurilide (2), the α,β-unsaturated γ-lactone obtained by an acid hydrolysis of menisdaurin.