Reductive cyclization of enones by titanium(IV) aryloxide and a Grignard reagent

The titanium-mediated cyclization of δ,ε-enones by using dichlorotitanium diphenoxide–cyclohexylmagnesium chloride diastereoselectively afforded cis-substituted cyclopentanols and was thus found to parallel the stoichiometric and catalytic titanocene-mediated reactions.