Formal Synthesis of (+)‐ and (–)‐Ferruginine

A formal synthesis of the naturally occurring (+)‐ferrugine and of its enantiomer starting from the commercially available tropinone is reported. The desymmetrization of tropinone was achieved through formation of diastereomeric unsaturated sulfoxides using the Andersen procedure. Introduction of the acetyl C(2) side chain was achieved by conjugate addition of lithiated ethyl vinyl ether to an unsaturated sulfone. N‐Boc‐Norferruginine, an advanced intermediate for the synthesis of ferruginine, was prepared in six steps and 19 % overall yield. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)