TiCl < inf > 4 < /inf > catalyzed tandem construction of C-C and C-O bonds: A simple and one-pot atom-economical stereoselective synthesis of spiro-oxindoles

Abstract

An atom-economical stereoselective synthesis of [{1-acetyl-5-methyl-6,8- dioxabicyclo(3.2.1)octane}-7-spiro-3′-(indolin-2′-one)] derivatives, containing both the oxindole and 6,8-dioxabicyclo(3.2.1)octane moieties via TiCl4 catalyzed coupling of 2-acetyl-6-methyl-2,3-dihydro-4H-pyran with isatin derivatives is described. © The Royal Society of Chemistry 2005.