Octahydropyrrolo[4,3,2-m,n]acridine derivatives. 2. 1-Aryl-4,4,8,8-tetramethyl-2,3,4,5,7,8,9,10-octahydropyrrolo[4,3,2-m,n]-acridin-10-ones and intermediates in their synthesis

A series of 9-aroyl-3,3,6,6-tetramethyl-1,2,3,4,5,6,7,8-octahydroxanthen-1,8-diones has been prepared from arylglyoxals and dimedone in a dehydrating medium; upon heating with ammonia these compounds are converted to 1-aryl-4,4,8,8-tetramethyl-2,3,4,5,7,8,9,10-octahydropyrrolo[4,3,2-m,n]acridin-10-ones. These reactions occur via the intermediate formation of tetrahydroindole derivatives.