Thermal and Photochemical Mechanisms for Cyclobutane Formation in Bielschowskysin Biosynthesis

Bencan Tang; Robert Simion; Robert S. Paton

doi:10.1055/s-0034-1379893

Synlett, Inhaltsverzeichnis

Synlett 2015; 26(04): 501-507
DOI: 10.1055/s-0034-1379893

letter

Thermal and Photochemical Mechanisms for Cyclobutane Formation in Bielschowskysin Biosynthesis

Bencan Tang

^aChemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA, UK

^bDepartment of Chemical and Environment Engineering, The University of Nottingham Ningbo China, 199 Taikang East Road, Ningbo 315100, P. R. of China

,

Robert Simion

^aChemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA, UK

^cPhysical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ, UK eMail: robert.paton@chem.ox.ac.uk

,

Robert S. Paton*

^aChemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA, UK

^cPhysical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ, UK eMail: robert.paton@chem.ox.ac.uk

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Abstract

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Abstract

The unique structure of furanocembranoid natural product bielschowskysin has provoked a number of biosynthetic hypotheses: quantum chemical calculations provide a means to assess the feasibility of postulated mechanisms in the construction of this unusual carbon skeleton. Calculations reveal that thermal closure is possible in water via an unusual concerted cyclobutane-forming transition state without the intervention of an enzyme. Photocycloaddition is computed to be extremely efficient, provided enol ether triplet sensitization can be achieved by an appropriate light source. The possible existence of a stable dicarbonyl intermediate presents a challenge for the thermal route, implicating a photochemical pathway in bielschowskysin biosynthesis.

Key words

biosynthesis - concerted - cyclization - DFT - transition states

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Referenzen

References and Notes
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Zusatzmaterial

Supporting Information