Sequential Metathesis in Oxa‐ and Azanorbornene Derivatives

Ring‐opening metathesis (ROM), when applied to the synthesis of bicyclic alkenes, is the basis of ring‐opening‐metathesis polymerisation (ROMP). This polymerisation reaction can be suppressed in the presence of a second open‐chain olefin thus combining the ROM with an intermolecular cross metathesis (CM). In conveniently substituted bicyclic derivatives a third metathetical reaction — ring closing metathesis (RCM) — can be achieved, giving new substituted bicyclic systems. In this account the results of these tandem metathetical reactions performed on oxa‐ and azabicyclic norbornenic derivatives are highlighted. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)