Isocomene: a novel sesquiterpene from Isocoma Wrightii. X-Ray crystal structure of the corresponding diol

Cameroonane, Prenopsane and Nopsane, Three New Tricyclic Sesquiterpene Skeletons

“…Recently, we reported on the constituents of this oil (see Table 1 and Scheme 1). [3] However, the structure of the three sesquiterpene alcohols (15,17,18), and the configuration of the four diastereomers of silphiperfolan-6-ol (19Ϫ22), remained unknown. We have now elucidated the structures of these compounds and, additionally, those of two other (new) sesquiterpenes; the alcohol 23 and the diene 24.…”

“…lelyi C. D. Adams (Compositae) contains only sesquiterpenes, which are mainly triquinanes. Besides the known tricyclic compounds, silphiperfol-5-(1, 3) and -6-ene (4), modhephen-2-ene (5), α-(6) and β-isocomene (7), silphiperfolan-7β-ol (12), presilphiperfolan-8-ol (13), silphiperfol-6-en-5-one (14) and 7-epi-silphiperfolan-6β-ol (20), the following compounds, three of which (15,17,18) have new skeletons, were found, for the first time, occurring naturally: presilphiperfol-7-ene (2), cameroonan-7-ol (15), an 11(7Ǟ8)-abeoEchinops giganteus var. lelyi C. D. Adams (Compositae) is an endemic species of Cameroon and Nigeria.…”

“…Diotis maritima (E, 5Ϫ7), [16] in Isocoma wrightii (5, 7), [17] [18] in Callilepis salicifolia [presilphiperfolanol (13), hydroxysilphinene, hydroxyisocomene], [22] in Artemisia cantabrica [12] , in A. chamaemelifolia [23] and in A. laciniata (presilphiperfolane and silphiperfolane derivatives).…”

Analysis of lipophilic fraction from leaves, inflorescences and rhizomes of Silphium perfoliatum L.

“…A temperature gradient was applied (35°C for 2 minutes, then increased by 4°C/min to 280°C). The qualitative analysis was carried out on the basis of MS spectra which were compared with the spectra of the NIST library (1992) and the LIBR (TR) terpenes library provided by Finnigan MAT (1990), and data available in literature (Bohlmann, Jakupovic 1979, 1980Bohlmann et al 1977Bohlmann et al , 1979aCareri et al 2001;Killops, Frewin 1994;Kowalski, Wolski in press 2004 online;Joulain, König 1998;Zalkow et al 1977Zalkow et al , 1978SCRI 2003). Identity of the compounds was confirmed by their retention indices taken from literature and own data (Kowalski 2001;Menut et al 1997;Weyerstahl et al 1997;Joulain, König 1998;Kowalski, Wolski in press 2004 online;Palá--Paúl et al 2002;Tellez et al 2002).…”

Cyclopentanoide Naturstoffe durch Alken‐Addition an Aromaten

“…Umlagerung des photochemisch angeregten Aromaten zu einer ,,Prefulven"-Zwischenstufe wie(13), die mit dem Alken zu (9) reagiert.…”