VALPARANE, A NEW DITERPENE SKELETON .4. ABSOLUTE STEREOCHEMISTRY OF VALPARONE, VALPAROLONE AND OTHER COMPOUNDS WITH VALPARANE SKELETON

The unsaponificable part of the hexane extract of Halimium viscosum ch emotype (Valparaiso, Zamora, Spain) afforded three hydrocarbons, an ep oxide, a ketone (valparone), five allylic alcohols and a seco derivati ve with valparane skeleton and an alpha,beta-unsaturated ketone with v alparolane skeleton. The majority of them have been correlated chemica lly. Chemical correlation between valparanes and valparolanes, absolut e stereochemistry determined by means of CD for valparone and the conf irmation of the absolute stereochemistry of valparanic and valparolani c compounds have been done by CD curve of the cyclohexanone obtained f rom valparolone.