抄録 The reaction of ketones with the titanocene reagent prepared by the treatment of 1, 1- bis (phenylthio) cyclobutane with the low valent titanium species Cp< SUB> 2 Ti [P (OEt)< SUB> 3]< SUB> 2 produced the corresponding alkylidenecyclobutanes. These compounds were successfully transformed into 2, 2- disubstituted cyclopentanones by the epoxidation and subsequent ring enlargement. The ...