Formal total syntheses of (–)-isoavenaciolide and (–)-ethisolide from L-quebrachitol

Abstract

The stereoselective conversions of the naturally occurring optically active cyclitol, L-quebrachitol 5, into the known synthetic intermediates, 3 and 4, for preparations of structurally interesting bislactones, (–)-isoavenaciolide 1 and (–)-ethisolide 2, respectively, are described. These bislactones, 3 and 4, were synthesized from the common intermediate 19, which was prepared by periodate oxidation of the bicyclic cyclitol derivative 17.