Efficient access to tricyclic compounds such as 2 and 3, which contain a seven-membered ring, is provided by the ruthenium-catalyzedintramolecular [5+2] cycloaddition of a 1,2,3-trisubstituted cyclopropyl enyne such as 1. Improved regioselectivity is observed when In(OTf)3 is used as the cocatalyst. (No cocatalyst: 2:3 6:1; cat. In(OTf)3 (10 %): 2:3 >20:1; Tf=trifluoromethanesulfonyl).