Aryl tetralines

Puri SG, Nazir A, Ghawla R, Arora R, Riyaz-ul-Hasan S, Amna T, Ahmed B, Verma V, Singh S, Sagar R, Sharma A, Kumar R, Sharma RK, Ghulam NQ, The endophytic fungus Trametes hirsuta as a novel alternative source of podophyllo-toxin and related aryl tetralin Yign2isi, J Biotechnol 122 494-510, 2006. 

Dayan, F.E., Kuhajek, J.M., Canel, G., Watson, S.B. and Moraes, R.M. (2003) Podophyllum peltatum possesses a p-glucosidase with high substrate specificity for the aryl-tetralin lignan podophyllotoxin. Biochim. Biophys. Acta, 1646,157-63. 

There has been much interest in the synthesis of lignan lactones of the aryl tetralin type, induced by the antitumour activity of podophyllotoxin relatives, and some short oxidative routes into the series have been pursued. In a typical reaction, in which both Cp—Cp and Cp—Car couplings occur, the cinnamyl cinnamate (297) was treated for 30 s with chromium trioxide-fluoroboric acid in acetonitrile. Three tetracyclic products were obtained, the lactones (298 19%) and (299 7%), and ( )-isopodophyllotoxone... 

An additional technique which yielded structural and stereochemical information in this series involves reduction with sodium in liquid ammonia. This also leads, accordihg to the conditions used, to two types of product, 28, a dihydroguaiaretic acid, and 29, again an aryl-tetralin. Chart 7 exemplifies the reaction sequence for veraguensin (47). 

Tetralin and 1-methylnaphthalene were reagent grade and were used after washing with sulfuric acid, alkali, and water and the subsequent distillation at 70°C under reduced pressure. Various additives and model compounds were reagent grade, and some of them were used after recrystallization. Phenyl naphthyl ether and phenyl 9-phenanthryl ether were synthesized by refluxing a mixture of aryl bromide, phenol, CU2O and X-collidine (12). 

Aryl phosphites inhibit the initiated oxidation of hydrocarbons and polymers by breaking chains on the reaction with peroxyl radicals (see Table 17.3). The low values of the inhibition coefficient / for aryl phosphites are explained by their capacity for chain autoxidation [14]. Quantitative investigations of the inhibited oxidation of tetralin and cumene at 338 K showed that with increasing concentration of phosphite /rises tending to 1 [27]. 

The aromatic ketones that occur or are used as fragrance and flavor materials are predominantly aryl methyl ketones, which include acetophenones and /3-naphthyl methyl ketone. Several acetylpolymethylindanes and -tetralins are commercially important as musk fragrances. 

Tetralins indanes. P205 can be used for cyclodehydration for substrates such as 1-aryl-l-pentanols or 2-aryl-2-hexanols. In the case of secondary alcohols, yields are sometimes improved by dehydration with TsOH to a styrene followed by cyclization with P2O5.1 The product of the second example is a known sesquiterpene, calamenene. 

In addition to alkenes, arenes can sometimes be used as radical acceptors in Sml2-mediated carbonyl-alkene couplings. For example, Schmalz reported extensive studies on ketyl additions to arenechromium tricarbonyl complexes 66,67 tetralin-Cr(CO)3 complex 49 underwent reductive carbonyl addition to the aromatic ring upon treatment with Sml2 to furnish the skeleton of the naturally occurring aryl glycoside pseudopterosin G (Scheme 5.37).66,67 Here, the bulky metal tricarbonyl group not only serves to control the... 

Alkyl-2-phenylquinazolines 9 are readily available by reaction of 5,S -dimethyl-A-(A-aryl-benzimidoyl)sulfimides 7 with enamines 8 in refluxing Tetralin (1,2,3,4-tetrahydronaphthalene). The mechanism of quinazoline ring formation probably involves a thermal cleavage of the imidoylsulfimides into imidoyl nitrenes, nitrene addition to the enamine double bond and subsequent rearrangement of the aziridine intermediate thus formed to the final product 9. Small amounts (10-15%) of 4-unsubstituted quinazolines 10 are obtained as byproducts. The formation of these byproducts involves a known intramolecular rearrangement of the benz-imidoylsulfimides employed. ... 

THF-soluble, pentane-insoluble products from the thermal dissolution of Kaiparowitz coal in tetralin comprise most of the soluble products. These materials are highly aromatic with a carbon aromaticity of about 70%. The aromatic portions are on the average highly substituted, possessing roughly one oxygen, 2.2 aryl or alkyl substituents, and 2.6 hydro-... 

Bei dcr Gasphascn-Blitzthcrmolyse bei 400-500° oder durch 15 min Erhitzen in Tetralin auf 207 entstehen aus 2,4-Diaryl-5-oxo-4,5-dihydro-l,3,4-oxadiazolen bzw. 2,5-Diaryl-2H-tetra-zolen nach Decarboxylierung bzw. Stickstoff-Eliminicrung 1,3-Diaryl-nitrilimine (s. Bd. El4b, S. 33ff.)202 557, die fast quantitativ zu 3-Aryl-lH-indazolen cyclisieren. 

Grignard solutions from alkyl or aryl halides can be obtained in yields almost as good as in ether by using a hydrocarbon such as benzene, toluene, xylene, or tetralin containing, 1 mole of tetrahydrofuran103 or of triethylamine104 per mole of magnesium. 

Indane and tetralin derivatives can be obtained by cyclodehydration of 3-aryl-1-alkanols and 4-aryl-l-alkanols, respectively.665 Isomerization does not occur in such reactions thus 4-phenyl-l-butanol gives tetralin and not 1-methylindane, and only 1,1-dialkylindanes are formed from the corresponding tertiary alcohols, e.g. ... 

Fig. (2). Crystal structure and absolute configuration of 2 -bromopodo-phy llotoxin illustrating the mostly planar tetralin backbone, the envelop conformation of the lactone ring, and the freely rotating aryl ring. 

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