The zirconacyclobutane derivative (tritox)2ZrC(=CH2)CH2CH2 (tritox = (
t-C4H9)3CO) with exocyclic methylidine group is formed unexpectedly fr
om (tritox)2ZrCl2 and vinyllithium. The compound was characterized by
H-1 and C-13 NMR spectra. The reaction mechanism is discussed. The Zr-
91 NMR spectrum of (tritox)2ZrCl2 is reported.