Preparation of transition metallacyclic complexes and utilization of the complexes for synthetic reactions are the subject of recent interest.'-5 However, most of the transition metallacyclic com-(1)(a) Grubbs, RH; Miyashita, A.; Liu, M.; Burk, PJ Am. Chem. SOC. 1977, 99, 3863.(b) Grubbs, RH; Miyashita, AJ Chem. Soc., Chem.
