6, 7-Dimethyl-1, 2, 3, 4-Tetrahydronaphthalene

Darzens et al. also used readily available malonic acid ester derivatives as substrates in reaction with sulfuric acid. " More recent studies and the NMR evidence demonstrated that for the cyclization of 2-methylallyl malonate 9 the use of anhydrous hydrogen fluoride is advantageous and leads to dimethyl tetrahydronaphthalene derivative 10. ... 

When malonate 9 is treated with polyphosphoric acid at room temperature, formation of lactone 11 is observed, similar to the Darzens procedure with the use of sulfuric acid. The structure of lactone is being retained during subsequent hydrolysis and decarboxylation of the exocyclic ester group followed up treatment with anhydrous hydrogen fluoride gives dimethyl tetrahydronaphthalene carboxylic acid 12. Hydrolysis and decarboxylation of 10 under standard conditions gives the same product 12. ... 

Further variations of the general scenario described in Scheme 4 consist in trapping adduct radical 48 before oxidation occurs7. This can be achieved if intramolecular radical additions are possible, as is the case in radical 62. Oxidation of 62 to the corresponding allyl cation is slower than 6-ew-cyclization to the chlorobenzene ring to form radical 63, which subsequently is oxidized to yield tetrahydronaphthalene 64 as the main product (equation 27). This sequence does not work well for other dienes such as 2,3-dimethyl-1,3-butadiene, for which oxidation of the intermediate allyl radical is too rapid to allow radical cyclization onto the aromatic TT-system. 

Tetrachloroterephthalic, see Chlorthal-dimethyl Tetraethyl monothiopyrophosphate, see Diazinon Tetraethyl p3U ophosphate, see Diazinon Tetrahydrodicyclopentadiene, see Chlordane Tetrahydronaphthalene, see Naphthalene... 

The a-pyrone adduct (430) on heating gave benzo[c]furan, isolated in 30% yield. Pyrolysis of l,4-oxido-l,2,3,4-tetrahydronaphthalene (431) at 650 °C and 0.1 Torr results in quantitative formation of benzo[c]furan. 1-Methyl-, 1,3-dimethyl-and l-benzyl-benzo[c]furanshave been prepared in quantitative yield by the flash pyrolysis technique (76TL2507). 

Polyketide synthesis. Polyketides (2) are obtained on reaction of the sodium lithium dianion (1) of methyl acetoacetate with dimethyl glutarates. When refluxed with Ca(OAc)2 in CH3OH, 2 cyclizes to l-oxo-l,2,3,4-tetrahydronaphthalenes in 30-75% yield.1... 

In addition, spirostomin, spiro[(2.5-dimethyl-5,6,7,8-tetrahydronaphthalene-l,4-dione)-8,6 -(pyrane-2, 5 -dione)], was identified from the ciliate Spirostomum teres 1 It exhibits toxic activities against predatory ciliates. 

A powerful oxidizer. Explosive reaction with acetaldehyde, acetic acid + heat, acetic anhydride + heat, benzaldehyde, benzene, benzylthylaniUne, butyraldehyde, 1,3-dimethylhexahydropyrimidone, diethyl ether, ethylacetate, isopropylacetate, methyl dioxane, pelargonic acid, pentyl acetate, phosphoms + heat, propionaldehyde, and other organic materials or solvents. Forms a friction- and heat-sensitive explosive mixture with potassium hexacyanoferrate. Ignites on contact with alcohols, acetic anhydride + tetrahydronaphthalene, acetone, butanol, chromium(II) sulfide, cyclohexanol, dimethyl formamide, ethanol, ethylene glycol, methanol, 2-propanol, pyridine. Violent reaction with acetic anhydride + 3-methylphenol (above 75°C), acetylene, bromine pentafluoride, glycerol, hexamethylphosphoramide, peroxyformic acid, selenium, sodium amide. Incandescent reaction with alkali metals (e.g., sodium, potassium), ammonia, arsenic, butyric acid (above 100°C), chlorine trifluoride, hydrogen sulfide + heat, sodium + heat, and sulfur. Incompatible with N,N-dimethylformamide. 

Many solvents form dangerous levels of peroxides during storage e.g., dipropyl ether, divinylacetylene, vinylidene chloride, potassium amide, sodium amide. Other compounds form peroxides in storage but concentration is required to reach dangerous levels e.g., diethyl ether, ethyl vinyl ether, tetrahydrofuran, p-dioxane, l,l-diethox) eth-ane, ethylene glycol dimethyl ether, propyne, butadiene, dicyclopentadiene, cyclohexene, tetrahydronaphthalenes, deca-hydrona-phthalenes. Some monomeric materials can form peroxides that catalyze hazardous polymerization reactions e.g., acr) lic acid, acr)Ionitrile, butadiene, 2-chlorobutadiene, chlorotrifluoroethylene, methyl methacrylate, styrene, tetrafluoroethylene,... 

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. ... 

The use of alkenes as sources of electrophiles in Friedel-Crafts alkylations has also been studied. The intramolecular alkylation of l-(2-tolyl)-( )-pent-3-ene gives 1,5-dimethyl-l,2,3,4-tetrahydronaphthalene in 95 % yield [55]. BF3 has been shown to form a complex with nitromethane which is particularly effective in catalyzing proton-initiated cascade cyclization like that shown in Eq. (29) [56]. 

So far, the occurrence of seven polycyclic musks has been reported. Their chemical names, chemical structures and molecular formulae are described elsewhere (Rimkus, 1999). The structural feature of all polycyclic musks is an indane or tetraline skeleton, which is highly substituted mainly by methyl groups (Fig. 1). 7-Acetyl-l,l,3,4,4,6-hexamethyl-l,2,3,4-tetrahydronaphthalene (AHTN, trade name Tonalide) and 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta[g]-2-benzo-pyrane (HHCB, trade name Galaxolide) are the most abundant ones. In this study, also 4-acetyl-1,1 -dimethyl-6-fert-butylindane (ADBI, trade name Celestolide) and 6-acetyl-l,l,2,3,3,5-hexamethylindane (AHMI, AHDI, trade name Phantolide) are investigated (Fig. 1). Important physicochemical properties of these compounds, which determine their environmental distribution and transport (e.g. solubility), are presented in chapter 4.1.1, in Ricking et al. (2003) as well as in Simonich et al. (2000). 

Otobain, 9a -(1,3-Benzedioxol-S-yt)-6,7,8,9-tetra-hydro-7o,80 -dimethylnaphtho[l,2-d]-l,3-dioxole 5,6-meth -ylenedioxy -2,3 -dimethyl -4-(3 ,4 -methyl enedioxy phenyl) -1,2,3,4-tetrahydronaphthalene otobite. mol wt... 

DDQ in trifluoroacetic acid (TFA) converts (-)-matairesinol dimethyl ether (183a) and (-)-kusunokinin (183b) into the dibenzocyclooctadienes (184a) and (184b) respectively [56]. However, DDQ in dioxane converts (-)-yatein (185) into the arylnaphthalene lactone (186) and the tetrahydronaphthalene lactone (187) [158] (scheme 71). 

Solvents used for paint removal are able to dissolve or considerably swell physically drying binders (e.g., vinyl chloride copolymers, cellulose nitrate, polyacrylates) and chemically cross-linked coatings (e.g., oil-based paints, dried alkyd resins, cross-linked polyester-melamine resins, cross-linked epoxy and isocyanate coatings) [14.237]. A combination of dichloromethane with low-boiling ketones or esters is particularly suitable. Small amounts of high-boiling solvents with a low volatility (e.g., tetrahydronaphthalene, solvent naphtha, methyl benzyl alcohol, or benzyl alcohol) are added to these mixtures to retard evaporation and increase the solvency. Modern paint removers do not contain chlorinated hydrocarbons, they are formulated on the basis of high boilers (e.g., dimethylformamide, dimethyl sulfoxide, propylene carbonate, and yV-methylpyrrolidone) in combination with alcohols and aromatics, or consist of aqueous, frequently alkaline or acidic systems. 

Diethylene glycol dimethyl ether (diglyme) Tetrahydronaphthalene... 

Terephthalic Acid, Dimethyl Dimethyl Terephthalate T etrahydronaphthalene Tetrahydronaphthalene... 

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