Abstract: | Sesquiterpene lactones of the guaianolide type — isolipidiol (I) and 8-epideacylcynaropicrin (II) — have been isolated from narrow-leaf hawk's-beard,Crepis tectorum L. On the basis of the results of an x-ray experiment the structure of (1R, 3S, 5R, 6R, 7R, 8R)-3,8-dihydroxy-cis,trans-guaia-4(15),10(14),-11(13)-trien-6,12-olide is proposed for (II).Institute of Organic Synthesis and Coal Chemistry, Kazakh Academy of Sciences, Karaganda. A. N. Nesmeynaov Institute of Organometallic Compounds, Russian Academy of Sciences, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 638–642, September–October, 1991. |