41929-05-9Relevant articles and documents
Sesquiterpene Cyclizations inside the Hexameric Resorcinarene Capsule: Total Synthesis of δ-Selinene and Mechanistic Studies
Zhang, Qi,Tiefenbacher, Konrad
supporting information, p. 12688 - 12695 (2019/08/12)
The synthesis of terpene natural products remains a challenging task due to the enormous structural diversity in this class of compounds. Synthetic catalysts are unable to reproduce the tail-to-head terpene cyclization of cyclase enzymes, which create this diversity from just a few simple linear terpene substrates. Recently, supramolecular structures have emerged as promising enzyme mimetics. In the present study, the hexameric resorcinarene capsule was utilized as an artificial cyclase to catalyze the cyclization of sesquiterpenes. With the cyclization reaction as the key step, the first total synthesis of the sesquiterpene natural product δ-selinene was achieved. This represents the first total synthesis of a sesquiterpene natural product that is based on the cyclization of a linear terpene precursor inside a supramolecular catalyst. To elucidate the reaction mechanism, detailed kinetic studies and kinetic isotope measurements were performed. Surprisingly, the obtained kinetic data indicated that a rate-limiting encapsulation step is operational in the cyclization of sesquiterpenes.
STABLE CARBOCATIONS FROM TERPENOIDS. I. GENERATION OF CARBOCATIONS FROM NATURAL SESQUITERPENES - DERIVATIVES OF HEXAHYDRONAPHTHALENE
Osadchii, S. A.,Polovinka, M. P.,Korchagina, D. V.,Pankrushina, N. A.,Dubovenko, Zh. V.,et al.
, p. 1070 - 1081 (2007/10/02)
Stable enantio- and diastereomeric carbocations were generated for the first time from optically active sesquiterpenes (-)-α- and (-)-γ-murolenes (I) and (II) and (+)-γ- and (+)-δ-cadinenes (III) and (IV), and their rearrangements in media with various acidities were studied at tempetatures between -120 and 20 deg C.By the reaction of solutions of salts of the stable cations with nucleophiles the transition was realized from unconjugated dienes (I-IV), isolated from the resin of Pinus silvestris L., to the conjugated dienes (-)-zonarene (V), (-)- and (+)-10-epizonarenes (VI, VII), (-)-trans-isocadinene (VIII), and (-)-bicyclosesquiphellandrene (IX), which had been discovered previously in other plant sources.