Phenanthrene tetrahydro

The 1H—NMR spectrum of 5,6,17,18-tetrahydro[2.2](2,7)phenan-threnopane (48) is compatible with the dihydrophenanthrene units being in an anti position. Dehydrogenation of 48 with 2,3-dichloro-5,6-dicyano-p-benzoquinone in benzene gave [2.2](2,7)phenanthrenophane which, owing to the similarity of its 1H—NMR spectrum to that of 2,7-dimethyl-phenanthrene, is assumed to have its phenanthrene units in the anti position 71>. 

Birch reduction of phenanthrene or 9-alkylphenanthrenes results in tetrahydro derivatives, but 9,10-dihydro derivatives are obtained in high yield by Li/NH3 reduction of phenanthrenes substituted by a 9-trimethylsilyl group (equation I). The trimethylsilyl group of 1 can be removed in quantitative yield with Bu4NF in... 

Over Raney Ni, phenanthrene may be hydrogenated to 1,2,3,4-tetrahydro-, s- and as-octahydro-, dodecahydro-, and perhydrophenanthrenes under the conditions described in Scheme 11.19.260... 

Some reductions that are not possible with triethylsilane and trifluoreacetic acid (5, 695 6, 616) can be effected with triethylsilane and boron trifluoride hydrate. Although benzene, naphthalene, and phenanthrene are not reduced, anthracene and naphthacene are reduced to tetrahydro derivatives in high yield. 1- or 2-Hydroxynaphthalene is reduced to tetralin in moderate yield. ... 

Reduction of stilbene [15] or diphenylacetylene [186] in DMF yields 1,2,3,4-tetra-phenylbutane, whereas phenanthrene [186] provides 9,9 10,10 -tetrahydro-9,9 -biphenan-threne. Hydrodimerization was also observed with benzalfluorene [193]. If DMF is... 

Reductive dimerization of unactivated aromatic hydrocarbons is rare, although, for example, formation of 9,9, 10,10 -tetrahydro-9,9 -biphenanthrene ( 40%) upon reduction of phenanthrene in DMF has been reported [246]. 

Phenanthrenes are formed by the reaction of 2-iodobiaryls with alkynes. The 1,2,3,4-tetrahydro derivatives are similarly obtained from the corresponding reaction with 2-iodo-1 -arylcyclohexenes. ... 

Heterocyclic Synthesis. - The reactions of phosphorus ylides with phenan-threne-9,10-quinone (113) have been used to prepare phenanthrene [9,10-x]-fused compounds with four, five, and six membered heterocyclic rings. (E)-4-carbethoxymethylene-l,2,3,4-tetrahydro-2-quinolones 114 have been obtained from the stereoselective reaction of 3-hydroxy-1,2,3,4-tetrahydroquinoline-2,4-diones and ethyl(triphenylphosphoranylidene)acetate. A -trifluoroacetylanilines 115 react with Ph3P=C02Et producing enamine derivatives 116 as a mixture of (E)- and (Z)-isomers. Enamines 116 are useful precursors for the synthesis of indoles and quinolones. 

Wiihrend fiir die Addition von Maleinsaureanhydrid an Benzol u. a. die Bildung von 2 1-Photoaddukten charakteristisch ist und ein l l-Addukt zwar als Zwisehenprodukt angenommen wird, jedoch nicht isoliert werden konnte, verlauft die Photocycloaddition von Maleinsaureanhydrid an Phenanthren unter Bildung des 1 1-Adduktes zu l,2,2a.l0b-Tetrahydro-(cydobuta- U -/pkenanthre.n)-1,2-diflarbon-saure-anhydnd (TIT)7 (s. a. S. 362) ... 

Analog wird 9-Cyan-phenanthren mit Methyl- oder Athyl-vinyi-ather in 2-Methoxy-bzw. 2-Athoxy-2a-cyan-l,2,2a,10b-tetrahydro-(cyclobuta-[l]-phenanthreny (60% d.Th.) tiber-fiihrt7. 

It is accepted5-7 8 that at least for simple unsubstituted aromatics (these are the usual model compounds that are employed they are recognized as an oversimplification but a necessary first step in this kind of work), they are hydrotreated to the corresponding naphthenes, with stepwise saturation of the aromatic rings in the case of polyaromatics. Figure 8.2 shows the reactions that can occur with (a) benzene to cyclohexane, (b) naphthalene to tetralin to decalin, and (c) phenanthrene to the dihydro-, tetrahydro-, octahydro-, and perhydrophenanthrene forms. 

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