Indeno indene

Dihydro-1-vinylnaphthalene (67) as well as 3,4-dihydro-2-vinylnaphtha-lene (68) are more reactive than the corresponding aromatic dienes. Therefore they may also undergo cycloaddition reactions with low reactive dienophiles, thus showing a wider range of applications in organic synthesis. The cycloadditions of dienes 67 and 68 and of the 6-methoxy-2,4-dihydro-1-vinylnaphthalene 69 have been used extensively in the synthesis of steroids, heterocyclic compounds and polycyclic aromatic compounds. Some of the reactions of dienes 67-69 are summarized in Schemes 2.24, 2.25 and 2.26. In order to synthesize indeno[c]phenanthrenones, the cycloaddition of diene 67 with 3-bromoindan-l-one, which is a precursor of inden-l-one, was studied. Bromoindanone was prepared by treating commercially available indanone with NBS [64]. 

C3NS-C3S2-C6-C6 9a,10-Dihydro-4bH-4bA4,9-dithia-10-aza-indeno[l,2-a]indene 12, 501... 

C3S2-C3S2-C6-C6 4b,9a-Dihydro-4bA4 9,10-trithia-indeno [ 1,2-a] indene 12, 501 4, 983/... 

Synonyms AI3-25584 EINECS 213-831-0 ENT 25584 Epoxy heptachlor HCE HE (3-Heptachlor epoxide Heptachloro epoxide l,4,5,6,7,8,8-Heptachloro-2,3-epoxy-2,3,3a,4JJa-hexahydro-4,7-methanoindene l,2,3,4,5,6,7,8,8-Heptachloro-2,3-epoxy-3a,4,7,7a-tetrahydro-4,7-methanoindene 5a,6,6a-Hexahydro-2,5-methano-2/f-indeno[l,2-A]oxirene 2,3,4,5,6,7,7 Hep tachloro-la,lb,5,5a,6,6a-hexahydro-2,5-methano-2//-oxireno[a]indene UN 2761 Velsicol 53-CS-17. 

The synthesis of a new class of compounds possessing the general structure 4,4,8,8-tetraalkyl-2,3 6,7-dibenzo-9-azabicyclo[3.3.1]nonane-l,5-diol (84) deserves mention since the basic skeleton is analogous to that of the pavines (Scheme 12) (124-129). Oxidation of a series of indeno[2,l-a]indenes 82 with chromic acid yielded dibenzocyclooctanediones 83. Treatment of these diketones with various amines resulted in a transannular reaction to afford species 84 in good yields. 

Indene Dihydroindene under Disubstituted and Polysubstituted Benzene Hydrocarbons Indene under Polycyclic Hydrocarbons, Nonaltemant Compounds with Two or Three Fused Rings Indeno(l,2,3-C(i0pyrene under Poiycyciic Hydrocarbons, Nonaltemant Compounds with More Than Five Fused Rings Iodine Iron... 

Imines derived from aniline and glyoxylic acid esters can be regarded as electron-poor 2-azadienes, in which an aromatic carbon—carbon double bond takes part of the diene system. In this context, Prato and Scorrano et al. were able to achieve the [4 + 2] cycloaddition of ethyl N-phenyl glyoxylate imines with dihydrofuran and indene leading to hexahydrof-uro[3,2-c]- and tetrahydro-7//-indeno[2,l-c]quinolines, respectively, in moderate to good yields (88JHC1831). Similarly, tetrahydroquinoline derivatives were formed by [4 + 2] cycloaddition of 1,2-bis(trimethylsily-... 

The indeno fused compounds (521) have been prepared in moderate yield by the photochemical reaction of 2,5-diaryl-l,3,4-oxadiazoles (519) with indene (77JOC1496) the reaction is thought to proceed via a diradical or betaine (520). These products react with isocyanates (RNCO) to give the triazepine system, e.g. (522) (76H(4)989). 

Photodimerization of the stilbene chromophore in small or medium ring systems is highly dependent upon the ring size. Indeno[2,l-a]indene (5) yields a 1 2 mixture of head-to-head head-to-tail dimers 28 and 29 (eq. 12) upon irradiation in... 

Dibenzo[b,fjpentalene (indeno[2,la]indene dianion) (32 ) has attracted much interest82). Its preparation via lithium metal reduction of 3 and from 32 by deprotonation with BuLi is very easy. NMR studies ( H, 13C and 7Li) of this system yield information on the electron distribution and the ion pair structure 60,81,82). The intermediate step, i.e. the radical anion 3 affords the estimation of charge densities. The starting material, viz. 3, is a 4nn system and is an excellent example of the Randic approach of polycyclic system s8). The H NMR spectrum of 32 shows the balance... 

TABLE 13. Arrhenius Parameters for Triplet Excitation Transfer from Indeno-[2,l-n]indene to Azulene"... 

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