TRICYCLIC SESQUITERPENES FROM RUDBECKIA-LACINIATA

Three phytotoxic sesquiterpenes were isolated from the roots of Rudbec kia laciniata, of which one of these was designated as lacinan-8-ol. I ts absolute configuration was established by the MNCB [2-(2'-methoxy-1 '- naphthyl)-3,5-dichlorobenzoic acid] method. It was chemically trans formed into the corresponding secondary allylic alcohol, whose absolut e configuration was also determined by MNCB and CD (circular dichroism ) allylic benzoate methods. (C) 1998 Elsevier Science Ltd. All rights reserved.