Metathesis condensation and isomerization reactions of allylic compounds were examined using Grubbs' second-generation ruthenium catalyst [Ru*]. Allyl alcohol and allyl cyanide undergo metathesis condensation releasing ethylene, with conversions being the highest reported for these substrates. However, competing olefin isomerization rather than metathesis can occur under certain conditions when heteroatoms are present at the allylic position to the olefin. (C) 2002 Elsevier Science B.V. All rights reserved.