| Abstract: | A series of endo-carbonyl-1,2-dihydro-(3,4,5,6-tetraphenyl)-N-substituted phthalimides ( 5a – e ) has been synthesized by the Diels-Alder reaction of tetracyclone ( 2 ) with some N-substituted maleimides ( 1a – e ). Decarbonylation of the adducts 5a , b afforded the dihydrophthalimides 6a , b . The dihydro adducts 7a , b and 8a , b were obtained when phencyclone ( 3 ) and 2,3-dimethylfurane ( 4 ) were allowed to react with maleimides 1a , b . Dehydrogenation of the dihydro adducts 5a , b , 6a , b , 7a , b , 8a , b yielded the adducts 9a , b , 10a , b , 11a , b , 12a , b , respectively. The dihydro adducts 6a , b , in contrast to the dihydro adducts 7a , b , reacted further with one molecule of a dienophile to provide the dihydro adducts 14a , b , 15a , b and 16a , b . The dihydro adducts 16a , b , were also obtained in one step when one molecule of 2 was allowed to react with two molecules of each of the N-substituted maleimides 1a , b . |
