A new synthesis for an isobenzofuran

CHED 509

Darci J. Trader, dtrader@siue.edu and James R. McClure. Department of Chemistry, Southern Illinois University at Edwardsville, Campus Box 1652, Edwardsville, IL 62026
The 1950 Nobel Prize in Chemistry was presented to Otto Diels and Kurt Alder for their mutual discovery of an experimental procedure known as the Diels-Alder Reaction. One molecular probe for the Diels-Alders reaction is a class of compounds known as isobenzofurans. The goal of this research is to generate a synthesis to create symmetrical and unsymmetrical isobenzofurans. Our synthesis utilizes 2,2-diphenyl-1,3-dioxalane as starting material. A halogen-metal exchange using n-butyllithium, the addition of an aldehyde, and then finally an acid catalyzed cyclization is employed to prepare the desired isobenzofuran. To date 2 isobenzofurans have been synthesized with our new synthetic route: 1,3-diphenylisobenzofuran (1,3-DPIBF) using benzaldehyde and 1-(4-chlorophenyl)-3-phenylisobenzofuran using 4-chlorobenzaldehyde. Isobenzofurans are of great significance to chemists because of their extensive pi electron system and their use as dienes in the Diels-Alder reaction.