Total synthesis of (±)-xanthocidin using FeCl3-mediated Nazarov reaction

The total synthesis of the antibiotic, (+/-)-xanthocidin (1), is described. The FeCl3-promoted fast Nazarov reaction of the beta-alkoxy divinyl ketone in the presence of t-BuOH provided the alpha-exo-methylene cyclopentenone, which is the core skeleton of this natural product. After methoxymethyl (MOM) esterification and protection of the reactive exo-methylene unit with a phenylseleno group, dihydroxylation, followed by oxidation, gave xanthocidin MOM ester. Finally, this ester was converted into (+/-)-xanthocidin (1) under mild conditions. (C) 2010 Elsevier Ltd. All rights reserved.