Titanium(IV) isopropoxide-catalysed reaction of alkylmagnesium halides with ethyl acetate in the presence of styrene. Non-hydride mechanism of ligandexchange in the titanacyclopropanes

The dependence of the yields of (E)-1-methyl-2-phenyl-1-cyclopropanol (3) o n the structure of the organomagnesium compounds and reagents ratio in the reaction of ethyl acetate with Grignard reagents, in the presence of styren e and catalytic amounts of Ti(OPri)(4), has been investigated. Butylmagnesi um bromide has been found to be the most suitable organomagnesium for the p reparation of 3 by this method. The use of (CD3)(2)CHMgBr for the generatio n of the titanacyclopropane intermediates led to the formation of 3. This r esult disagreed with the hydride mechanism of the ligand exchange for 2-phe nyltitanacyclopropane (4) formation. (C) 1999 Elsevier Science Ltd. All rig hts reserved.