Ring-Closing Metathesis of Titanium–Carbene Complexes Prepared from Thioacetals Having a Carbon–Carbon Double Bond

The ring-closing metathesis proceeded to give cycloalkenes in good yields when diphenyl thioacetals having a carbon–carbon double bond were treated with the low-valent titanium species Cp2Ti[P(OEt)3]2 in THF at room temperature and then at reflux. This methodology is successfully applied to the preparation of cyclic ethers and sulfides.