The enantioselective syntheses of the natural product (+)-aspercyclide A and also an analogue devoid of the aryl aldehyde moiety are described.

J. J.P. Sejberga, L. D. Smith, R. J. Leatherbarrowa, A. J. Beavilb, A. C. Spivey, 'Enantioselective synthesis of (+)-aspercyclide A', Tetrahedron Lett. 2013, ASAP DOI: 10.1016/j.tetlet.2013.07.038

An efficient synthesis of the natural IgE-FceRI PPI inhibitor (+)-aspercyclide A was achieved through the use of a Krische iridium-catalyzed diastereo- and enantioselective alkoxyallylation to form the key mono-protected anti-diol intermediate 4, in high optical purity. A derivative of the natural product, containing an oxathiazine dioxide ring in place of the ring-A hydroxyaldehyde unit has also been prepared and found to display comparable ELISA activity to the parent compound, indicating that the aldehyde group is not the key determinant of activity.