The syntheses of various oxidation states of the novel benzo [l, 2]cyclohepta [3,4,5-d, elisoquinoline ring system is described. The ring system was obtained by the Schmidt rearrangement, with exclusive alkyl migration, of 1 , 6 , 7 , l lb-tetrahydro -2Hdibenz-[cd, hlazulen-2-one and by a Bischler-Napieralski reaction of suitable derivatives of 10, 11-dihydro-SH-dibenzo[a, dlcycloheptene -5 -methylamine. 4,5,10,11-Tetramethoxy derivatives of the new ring system were best prepared by a Pictet-Spengler reaction of the appropriate amine.The 10, 11 -dihydrobenzo[a, dlcycloheptene ring system (I) i s present in several compounds with interesting biological properties (I) and it was considered useful to elaborate this into other systems by fusing an additional ring, e . g . , between positions 4 and 5. We chose a s starting material for this investigation, 10,11 -dihydro-5H-dibenzo[a, dlcycloheptene -5 -ylideneacetic acid (11) ( 2 ) which was smoothly hydrogenated to the saturated acid (III)using Raney Nickel and this latter compound cyclized with anhydrous hydrogen fluoride to give 1,6,7, l l btetrahydro-2H-dibenz[cd, hlazulen-2-one (W). It was converted to the oxime in high yield. Reduction of N with lithium aluminum hydride, o r preferably with sodium borohydride, gave hhydroxy-l,6,7, l l btetrahydro-2H-dibenz[cd, hlazulene (V) . Dehydration of this alcohol was accomplished by the elegant method of Traynelis, et al., (3) giving the hydrocarbon (VI) in 96% yield. The 1,llb-position of the double bond was assigned on the basis of the n.m.r. spectrum which showed one vinylic proton a s a triplet centered at 3.23 T . The benzylic proton at the 2-position showed up a s a doublet centered at 6.55 T , and the four equivalent (4) protons of the ethylene bridge gave a sharp singlet at 6.91 T.Since this work was completed, the synthesis of IV has been reported by van der Stelt, et al., (5) from the acid chloride of 111, and Galantay, et al., (6) have reported the synthesis of the fully unsaturated 2Hdibenzlcd, hlazulen-2-one.Attempts to realize the Beckmann rearrangement of the oxime of IV under various conditions were without success, but treatment of IV with sodium azide in molten trichloroacetic acid at 70" gave a single lactam in 80% yield. It was the isocarbostyril (VIII) rather than the expected carbostyril derivative (VII). The structure of VIII was assigned by examination of the ultra-violet spectra of its lithium aluminum hydride reduction product IX which was unchanged when taken as the hydrochloride salt, or, in the presence of sodium hydroxide. The formation of this isocarbostyril was not anticipated in view of the expected behaviour of cyclic aryl alkyl ketones in the Schmidt rearrangement (7) where aryl migration is usually observed. We considered that the high yield of the isocarbostyril (VIII) might have been due to the ridigity of the system (IV) imposing a configurational preference on an assumed iminodiazonium ion intermediate. Thus, the Schmidt rearrangement of the indanone (X) formally derived from IV...