- Superacidic low-temperature cyclization of terpenols and their acetates
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The superacidic low-temperature cyclization of terpenols and their acetates be fluorosulfonic acid represents a highly efficient chemo- and structurally selective and stereospecific process.Homoallylic alcohols (α-isomers of cycloterpenols) are the products of cyclization of terpenols; the configuration of the hydroxymethyl group in the products is predetermined by the configuration of the allylic double bond in aliphatic or partially cyclized precursors.The cyclization of terpenyl acetates yields monoacetates of fully cyclized diastereomeric primary-tertiary γ-diols.Their stereochemistry also depends on the configuration of the allylic double bond in the starting substrates. - Key words: terpenols; terpenyl acetates; cyclization, fluorosulfonic acid, drimanes, isoagathanes, scarlanes.
- Vlad, P. F.,Ungur, N. D.,Nguen Van Hung,Perutsky, V. B.
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p. 2391 - 2403
(2007/10/03)
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- Cyclization and Rearrangements of Farnesol and Nerolidol Stereoisomers in Superacids
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Acid-catalyzed cyclization of 2,3-trans- and 2,3-cis-farnesol proceeds regioselectively and stereospecifically, yielding drimenol and epi-drimenol, respectively.The trans and cis isomers of nerolidol undergo carbo- and heterocyclization reactions.The trans isomer gives tricyclic caged hydrocarbons with new skeletal types, while the rearrangements of the cis isomer produce derivatives of 2-oxabicyclodecane.The ICAR computer program was used to derive reasonable mechanisms for the acid-catalyzed transformations of nerolidol, and the probability of the mechanisms was evaluated by the molecular mechanics method.
- Polovinka, Marina P.,Korchagina, Dina V.,Gatilov Yurii V.,Bagrianskaya Irina Yu.,Barkhash, Vladimir A.,et al.
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p. 1509 - 1517
(2007/10/02)
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- CYCLIZATION OF ACYCLIC ISOPRENOIDS V REARRANGEMENT OF STEREOISOMERIC FARNESOLS AND NEROLIDOLS IN SUPERACIDS
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The cyclization of 2,3-trans- and -cis-farnesols in superacids is structurally selective and stereospecific, giving drimenol and epidrimenol respectively.Depending on the reaction conditions, trans- and cis-nerolidols undergo carbo- or hetero-cyclization, to give in the first case tricyclic bridged hydrocarbons with a novel skeleton, and in the second case a 2-oxabicyclodecane.
- Polovinka, M. P.,Unzur, N. D.,Perutskii, V. B.,Korchagina, D. V.,Gatilov, Yu. V.,et al.
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p. 1871 - 1885
(2007/10/02)
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