Synthesis of various heterocycles containing 7- and 8-membered rings was investigated. Starting ene-ynamides were easily synthesized by the known method. When a toluene solution of ene-ynamide was stirred in the presence of a catalytic amount of the second-generation ruthenium carbene complex under ethylene atmosphere, RCM proceeded smoothly to provide heterocyclic compound having a diene moiety in good to high yield. Various substrates could be used for this reaction to afford the cyclic dienamide derivatives. When the construction of 8-membered rings was examined, the lower temperature and the longer reaction time gave good results. Substituent on the alkyne of ynamide affected the yield of the cyclized product. The cyclic dienamide derivatives obtained in this reaction were subjected to the Diels-Alder reaction to provide fused cyclic compounds in good yields.
