Synthesis of an Advanced C10–C32 Spiroacetal Fragment and Assignment of the Absolute Configuration of Spirangien A


  • This work was supported by the EPSRC (GR/S19929/01), Homerton College, Cambridge (E.A.A.), and Merck Research Laboratories (A.D.F.). We thank Dr. J. Niggemann (GBF, Braunschweig) for the NMR spectra of degradation fragment 3 and Dr. J. P. Scott (Merck Sharp & Dohme Research Laboratories, Hoddesdon) for discussions.


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A bit on the side: A highly convergent and flexible synthetic strategy has been developed for spirangiens A and B that made use of a common stereotetrad building block and led to an advanced C10–C32 spiroacetal fragment, thus enabling the unambiguous assignment of the absolute configuration of these potent cytotoxic polyketide metabolites isolated from the myxobacterium Sorangium cellulosum.