Hydronaphthalenes

IDA reactions to give fused 6 5 (hydroindene) and 6 6 (hydronaphthalene) ring systems are usually favorable reactions. 

As in the [22]porphyrin(3.1.3.1) series, the cyclohexene moieties being part of the bridges originate from the preparation of the dimers from dimethylpyrrole and a hydronaphthalene diketone by acid-catalyzed condensation. The synthetic approach developed by Franck2b has the advantage over the foregoing method that more stable conventional pyrroles and dipyrryl-methanes can be used to form the macrotetracycle in a stepwise manner. 

The first step in this preparation, the epoxidation of 1,4,5,8-tetra-hydronaphthalene, exemplifies the well-known selectivity exerted by peracids in their reaction with alkenes possessing double bonds that differ in the degree of alkyl substitution.12 As regards the method of aromatization employed in the conversion of ll-oxatricyclo[4.4.1.01-6]-undeca-3,8-diene to l,6-oxido[10]annulene, the two-step bromination-dehydrobromination sequence is given preference to the one-step DDQ-dehydrogenation, which was advantageously applied in the synthesis of l,6-metliano[10]annulene,2,9 since it affords the product in higher yield and purity. 

When electron-withdrawing groups are introduced at the vinyl moiety, ary-lethenes may behave as dienophiles. Thus a-trifluoromethyl styrene (111) interacted with Danishefsky s diene (12b) under thermal or high pressure conditions [37] to regioselectively afford a 1 1 mixture of cycloadducts which were then converted to 4-phenyl-4-trifluoromethyl-2-cyclohexen-l-one (112) (Equation 5.12). A direct access to angularly trifluoromethyl-substituted tricyclic compounds may be achieved by cycloaddition of the l-trifluoromethyl-3,4-di-hydronaphthalene (113) with diene 12b (Equation 5.13). 

Intermolecular cycloadditions or Diels-Alder reactions have proved to be a successful route to several valuable intermediates for natural product syntheses. In creating new chiral centers, most of these reactions apply single asymmetric induction. As mentioned in Chapter 3, in the asymmetric synthesis of the octa-hydronaphthalene fragment, the Roush reaction is used twice. Subsequent intramolecular cyclization leads to the key intermediate, the aglycones, of several natural antitumor antibiotics. On the other hand, the Diels-Alder reaction of a dienophile-bearing chiral auxiliary can also be used intramolecularly to build... 

Isotetralin, 54, 11 ISOXAZOLE ANNELATION REACTION 1-METHYL-4,4a,5,6,7,8-HEXA-HYDRONAPHTHALEN-2 (3H) -ONE,... 

Under nominally aprotic conditions, 1,2-protonation dominates in naphthalene. Reduction of naphthalene in anhydrous acetonitrile containing tetraethylammo-nium p-toluenesulfonate yields 1,2-di-hydronaphthalene, which is subsequently... 

CS030 Sakakibara, 1., Y. Ikeya, K. Hayashi and H. Mitsuhashi. Three phenyldi-hydronaphthalene lignanamides from fruits of Cannabis sativa. Phytochemistry 1992 31(P) 3219-3223. 

UDMH is known to be miscible with the following wafer, benzene, triethyl benzene, toluene, kerosene, ethyl alcohol, isobutyl alcohol, n-butyl ether, n-amyl ether, n-hexyl ether, diethyl ether, petroleum ether, petroleum naphtha, n-heptane, n-hexane, n-octane, n-decane, n-dodecane, n-hexadecane, cyclohexane, 1,2-dimethyl cyclohexane, phenyl cyclohexane, n-tetradecane, trichloroethylene, dichloroethylene, perchloroethylene, 1,1,1-trichloroethane, triethyl amine, ethylenediamine, diethylene triamine, acetonitrile, aniline, cumene, tetra-hydronaphthalene, tetraethylene pentamine, ethylene glycol and hydrazine (Ref 4)... 

TETRAHYDRO- NAPHTHALENE 1,2,3,4-Tetra-hydronaphthalene, Tetralln, Tetranap Combustible Liquid 2 0... 

In this series of spiro-piperidines selectivity was achieved by replacement of the initial substituted tetra-hydronaphthalene moiety (cpd. 5) by acenaphthenyl (10-fold cpd. 6) and finally by hexahydro-1 H-phenalene (100-fold Ro 64-6198)... 

Polygodial [6754-20-7], 5,5,8a-Trimethyl-1,4,4a,5,6, 7,8,8a-octa-hydronaphthalene-1,2-dicarbaldehyde, C15H2202, Mr 234.33. Trade name Kolorex (NZ). 

J. Herscovici, S. Delatre, L. Boumaiza, and K. Antonakis, Stereocontrolled routes to functionalized [1,8-bcJ-naphthopyran—a study on the total synthesis of quassinoids and tetra-hydronaphthalene antibiotics, J. Org. Chem. 58 3928 (1993). 

There are few examples of C-terminal helix mimetics and, while their utility has been considered uncertain,11361 successful helix induction has been described using tetra-hydronaphthalene compounds represented by 16.11351 Templated peptide 17, for example, demonstrates 81% helix by CD while control peptide 18 exhibits only 50% helix under the same conditions (Scheme 7). For the preparation of tetrahydronaphthalene templates and their attachment to peptides, see refs.1134,1351... 

Fluonne replacement in condensedpolyfluoroaromatics can be a complicated process In perfluoroanthracene the fluonne reactivity toward replacement by methoxide follows the order 2-F > 9-F [14], whereas in periluoropyrene, the reactivity decreases in the senes 1-F > 3-F > 6-F> 8-F [75] In decafluoro-l,4-di-hydronaphthalene, the 6-fluonne is most easily replaced [75] (equation 10) All fluonne atoms in perfluoronaphthalene are replaced by alkoxide or aryloxide with Vl,Af3-dimethylimidazolidm-2 one (DMI) as the solvent [76] (equation 11)... 

Arpe, H. J. Naphthalene and Hydronaphthalenes to Nuclear Technolog>, Vol. 17, 5th Edition, John Wiley Sons, Inc, New York, NY, 1996,... 

The following solvents are now manufactured on the large scale for industrial purposes ethylene dichloride, di-, tri-, and tetra-chloroethy-lene, tetrachloroethane, dichloroethyl ether, hexahydrobenzene, cyclo-hexanol, tetra- and deca-hydronaphthalene (tetralin and dekalin), triacetin, ethylene glycol, butyl alcohol, diacetone alcohol, ethyl lactate, isopropyl ether, etc. 

Ketone oximes of the hydronaphthalene series can successfully be transformed into pyrroles. Thus, 4,5-dihydrobenzo[g]indole (38) was prepared in one stage (yield 70%) from a-tetralone oxime (37) and acetylene (Scheme 21) (78ZOR1119). 

The naphthalene cation radical can react with the hydrogen atom. The 1-hydronaphthalene cation resulting from this reaction is more stable than the reactants. This process has no activation barrier. After its formation, the 1-hydronaphthalene cation can absorb a photon and lose one of the two hydrogen atoms on carbon 1, since these hydrogens are more weakly bound than the aromatic hydrogens. Because the C-D bond is slightly stronger than the C-H bond, the reaction mentioned here can lead to some deuterium enrichment (Bauschlicher 1998). 

List B, giving examples of liquids where a degree of concentration is necessary before hazardous levels of peroxides will develop, includes several common solvents containing one ether function (diethyl ether, ethyl vinyl ether, tetrahydrofuran), or two ether functions (p-dioxane, 1,1 -diethoxyethane, the dimethyl ethers of ethylene glycol or diethylene glycol ), the secondary alcohols 2-propanol and 2-butanol, as well as the susceptible hydrocarbons propyne, butadiyne, dicyclopentadiene, cyclohexene and tetra- and deca-hydronaphthalenes. Checking stocks at 12 monthly intervals, with peroxidic samples being discarded or repurified, is recommended here [1],... 

The strong reactivity of this compound has been employed in the synthesis of triazasteroids with the nitrogen atoms situated in different positions (77TL4141). Thus, reaction of the l,2,3-triazolin-3,5-dione (obtained by t-butyl-hypochlorite oxidation of the l,2,4-triazolidine-3,5-diones) with diverse 1-vinyl-hydronaphthalene derivatives gave the expected adducts,... 

When the anisolium complex generated by the addition of MVK to the 2-methoxytetra-hydronaphthalene complex 59 is utilized in the above cyclization sequence, the tricyclic oxonium complex 61 is generated (Scheme 6). Deprotonation of 59 with pyridine forms the extended vinyl ether complex 60, which cydizes and eliminates water to form 61 when exposed to TBSOTf. Hydrolysis of 61, followed by oxidation of the metal fragment, yields the dienone 62 in 15 % yield (based on 59). 

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