Scheme 59.
Intramolecular ruthenium-catalyzed [2+2+2] cycloadditions of alkynes with alkenes and allenes reported by Itoh and Yamamoto, Sato, Mori and Saito.
Intramolecular ruthenium-catalyzed [2+2+2] cycloadditions of alkynes with alkenes and allenes reported by Itoh and Yamamoto, Sato, Mori and Saito.