Stereochemical π-facidal selectivity of the diels-alder reaction of benz[a]aceantherylene and 1,4-diphenylbenz[a]aceanthrylene

摘要

The Diels_Alde (D-A) reaction of the twisted hydrocarbon 1,4-diphenylbenz[a]aceanthrylene (4) with dienophiles maleic anhydride, bromomaleic anhydride, and N-phenylmaleimide and with benzyme is reported. The stereochemistry of the products derived from the D-A reaction of 4 is compared with the products derived from reaction of planar benz[a]aceanthrylene (5) with maleic anhydride as a model. The endo regiochemical π-facial selectivity of 4 appears to be the results of the steric effect of a phenyl substituent as the transition state is reached.