Total syntheses of multiple cladiellin natural products by use of a completely general strategy

Clark, J.S. , Berger, R., Hayes, S.T., Senn, H.M. , Farrugia, L.J., Thomas, L.H., Morrison, A.J. and Gobbi, L. (2013) Total syntheses of multiple cladiellin natural products by use of a completely general strategy. Journal of Organic Chemistry, 78(2), pp. 673-696. (doi: 10.1021/jo302542h)

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Abstract

The enantioselective total syntheses of 10 cladiellin natural products have been completed, starting from the known allylic alcohol (+)-14, which can be prepared in large quantities. The bridged tricyclic core of the cladiellins has been constructed via three ring-forming reactions: (i) an intramolecular reductive cyclization between an aldehyde and an unsaturated ester, mediated by samarium(II) iodide, to form a tetrahydropyranol; (ii) reaction of a metal carbenoid, generated from a diazo ketone, with an ether to produce an ylide-like intermediate that rearranges to produce E- or Z-oxabicyclo[6.2.1]-5-undecen-9-one; and (iii) a Diels–Alder cycloaddition reaction to construct the third ring found in the core structure of the cladiellins. The key ring-forming reaction, in which a diazo ketone is converted into a bridged bicyclic ether, can be tuned to give either of the isomeric oxabicyclo[6.2.1]-5-undecen-9-ones as the major product by switching from a copper to a rhodium catalyst and selecting the appropriate reaction conditions. The tricyclic products obtained from the three-step sequence involving the Diels–Alder cycloaddition reaction can be employed as advanced intermediates to prepare a wide range of cladiellin natural products.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Clark, Professor Stephen and Farrugia, Dr Louis and Berger, Miss Raphaelle and Senn, Dr Hans and Thomas, Dr Lynne
Authors: Clark, J.S., Berger, R., Hayes, S.T., Senn, H.M., Farrugia, L.J., Thomas, L.H., Morrison, A.J., and Gobbi, L.
College/School:College of Science and Engineering > School of Chemistry
Journal Name:Journal of Organic Chemistry
ISSN:0022-3263
Published Online:06 December 2012

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