Investigation of arene-arene interaction in stereoselective MCPBA epoxidation

Effect of arene-arene interaction in stereoselective MCPBA epoxidation was investigated using 5,6-dimethyl-2-phenyl-3a,4,7,7a-tetrahydroisoindole-1,3- diones 1. From the good correlation between the stereoselectivity of the pr oducts and Hammett's coefficients of para-substituents (sigma (P)) on the p henyl group, it was found that polar/pi interaction between the phenyl grou p and MCPBA is the main interaction for controlling the stereoselectivity i n the reaction. Other arene-arene interactions, charge-transfer complexatio n and edge-to-face interaction, were assumed to be much weaker than polar/p i interaction in this reaction.