- MOLECULAR REARRANGEMENTS OF CARYOPHYLLENE AND ISOCARYOPHYLLENE 4,5-EPOXIDES IN SUPERACIDIC MEDIA
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Enantiomeric stable carbocations were generated from the epimeric pair of optically active isocaryophyllene 4β,5β- and 4α,5α-epoxides in the superacid.The subsequent molecular rearrangement path is determined by participation of the ? and ? bonds in opening of the epoxide ring.For the case of caryophyllene 4β,5α- and 4α,5β-epoxides it was shown that rearrangement to compounds with the clovane or caryolane skeleton respectively is possible.The rearrangement of a compound of the caryophyllane type to compounds of the selinane group was realized for the first time.For the case of caryophyllene 4β,5α-epoxide it was shown that the generation temperature of the ions has a significant effect on the preferred position of the cationic center.
- Nisnevich, G. A.,Korchagina, D. V.,Makal'skii, V. I.,Dubovenko, Zh. V.,Barkhash, V. A.
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p. 441 - 453
(2007/10/02)
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- REARRANGED CARYOPHYLLENES BY BIOTRANSFORMATION WITH CHAETOMIUM COCHLIODES
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Biotransformation of caryophyllene by Chaetomium cochliodes DSM 1909 (=ATCC 10195) leads to 4,5-epoxy-caryophyllene-7,12-diol as the main product.The hydroxylation of the geminal methyl groups is not very stereospecific, but as with Diploida gossypina the main product possesses the 11R-configuration.Side-reactions are ring contraction or formation of clovanes, probably via epoxide rearrangements.The use of mono- or diepoxy-caryophyllene as the substrate does not increase the yields significantly.Instead, diepoxy-caryophyllene gave a punctatin derivative.The same molecular framework, but with a different configuration, was observed among the fermentation products from Diplodia gossypina, which supports the assumption that a caryophyllane is the precursor of this class of antibiotics.
- Abraham, Wolf-Rainer,Ernst, Ludger,Arfmann, Hans-Adolf
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p. 757 - 763
(2007/10/02)
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