Format:
Online-Ressource
ISSN:
1439-7633
Content:
Abstract: Cyclase‐free at last: A methylene‐interrupted meso‐bis‐epoxide was stereoselectively converted into dihydroxy‐tetrahydrofuran derivatives with excellent de and ee values through an enzyme‐triggered nucleophilic hydrolysis/cyclisation cascade. Molecular modelling showed that the point of enzyme attack was determined by the stereospecificity of the epoxide hydrolase, whereas the stereochemical course of the cyclisation step was solely governed by Baldwin's rules and did not invoke the involvement of a “cyclase”. In contrast with electrophilic enzyme‐catalysed cyclisations in terpenoid biosynthesis, cyclisations of tetrahydrofuran moieties found in several groups of natural products, such as annonaceous acetogenins, neurofurans and phytooxylipins, appear to proceed through a nucleophilic cascade mechanism starting from bis‐epoxy fatty acid precursors. This hypothesis was verified by epoxide‐hydrolase‐catalysed hydrolytic ring‐opening/cyclisation cascades starting from a methylene‐interrupted meso‐bis‐epoxide model substrate, which furnished the corresponding THF products with excellent de and ee values. Molecular modelling showed that the points of enzyme attack were consistent with the stereospecificities of the enzymes, whereas the stereochemical courses of the cyclisation were solely governed by Baldwin's rules and did not invoke the involvements of a “cyclase”.
In:
volume:10
In:
number:10
In:
year:2009
In:
pages:1697-1704
In:
extent:8
In:
ChemBioChem, Weinheim : Wiley-VCH, [2000]-, 10, Heft 10 (2009), 1697-1704 (gesamt 8), 1439-7633
Language:
English
DOI:
10.1002/cbic.200900176
URN:
urn:nbn:de:101:1-2023041415543374824330
URL:
https://doi.org/10.1002/cbic.200900176
URL:
https://nbn-resolving.org/urn:nbn:de:101:1-2023041415543374824330
URL:
https://d-nb.info/1286273099/34
URL:
https://doi.org/10.1002/cbic.200900176
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