(—)β-Lycorane

Hydrogenation of diacetyllycorine (Ib) was found to be the most effective route for conversion of lycorine (Ia) into β-dihydrocaranine (II). The Hauptmann reduction of 1-deoxy-β-dihydrolycorin-2-one (XII) or the Clemmensen reduction of 1-0-acetyl-β-dihydrolycorinone (XI) followed by hydrogenation afforded (—)β-lycorane (X), which, in view of the sequence of reactions used in these transformations, is considered to have the same configurational structure as the skeleton of β-dihydrocaranine. This lycorane was also obtained by the Hauptmann reduction of β-dihydrocaranone (VIII). A procedure for preparing (—)-lycorane (V) from 1-0-acetyllycorin-2-one (XIV) was also worked up.