Department of Chemistry, Faculty of Engineering, Gifu University, Yanagido 1-1, Gifu 501-1193, Japan
Abstract:
The frontier molecular orbital of 5-phenylcyclopentadiene was predicted on the basis of the orbital mixing rule to deform to favor the Diels-Alder reaction in a syn contrasteric manner. The prediction was substantiated experimentally by the reactions of 5-methyl-5-phenylcyclopentadiene with dienophiles to afford the syn attack products, exclusively.