Diels-Alder Reaction

The present reagent 1 is a highly reactive dienone and reacts rapidly with various dienophiles to give the cyclic adducts. This reaction proceeds stereoselectively. For example, the reaction with p-substituted styrene produces preferentially an endo-oriented adduct. In the reaction with an electrone deficient, such as maleic anhydride, only an endo-oriented adduct is produced. Since the present dienone is colored intense orange while the adduct is faded, the progress of reaction can be monitored by observation of the color change.