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Updated: May 31, 2026

Metal-free Synthesis of Ynones from Acyl Chlorides and Potassium Alkynyltrifluoroborate Salts
Published on: February 24, 2015
Synthesis of the anti-HIV agent (-)-hyperolactone C by using oxonium ylide formation-rearrangement
David M Hodgson1, Stanislav Man
1Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Oxford, UK. david.hodgson@chem.ox.ac.uk
Abstract:
Starting from readily available (S)-styrene oxide an asymmetric synthesis is described of the naturally occurring anti-HIV spirolactone (-)-hyperolactone C, which possesses adjacent fully substituted stereocenters. The key step involves a stereocontrolled Rh(II) -catalysed oxonium ylide formation-[2,3] sigmatropic rearrangement of an α-diazo-β-ketoester bearing allylic ether functionality. From the resulting furanone, an acid-catalysed lactonisation and dehydrogenation gives the natural product.
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