Methoxy tetrahydronaphthalene

In addition to naphthyl substituted alkynes, 2-methoxy-tetrahydronaphthalen-1-yl- and 2-methoxy-6-methylphenyl alkynes were shown to be suitable substrates affording the corresponding pyridones with e.e.s >90%. 

Detellurative methoxylation of alkyl phenyl tellurides (typical procedure)2-Methoxy 3-phenyltelluro-l,2,3,4-tetrahydronaphthalene (1.85 g, 5 mmol) is treated with MCPBA (3.3 g, 15 mmol) in MeOH (30 mL) at 25°C with stirring. After 1 h the mixture is treated with aqueous Na2S203 followed by aqueous NaHCOj and extracted with ether (3x30 mL). The extract is dried (MgS04) and evaporated, to leave a residue which is purified by Si02 TLC (eluting with hexane/EtOAc, 4 1) to afford pure tranx-2,3-dimethoxy-l,2,3,4-tetrahy-dronaphthalene (0.37 g, 1.94 mmol) and the c/x-isomer (0.15 g, 1.76 mmol (54%)). 

Methoxy-7-methoxycarbonyl-1,2,3,4-tetrahydronaphthalene 2-Naphthalene-carboxylic acid, 5,6,7,8-tetrahydro-3-methoxy-, methyl ester (78112-34-2), 65, 98 Methyl acrylate (96-33-3), 66, 54, 59 dimerization by Pd(II), 66, 52 Methylamine, N-benzylidene-, 65, 140 METHYL 4-0-BENZOYL-6-BROMO-6-DEOXY-a-0-GLUCOPYRANOSIDE ... 

Of the disubstituted tetrahydronaphthalenes (V and VI), only Vic is a new compound, but Va was prepared by a new process. Furthermore, we had completed our synthesis of Vb before the appearance of the almost identical preparation of O Fabrell et al. [3] The hydroxyketone VI6 was prepared by the general method of O Farrell et al. [3], but our synthesis proceeded in much higher yield. Some unique results also have been obtained by subjecting 3-methoxy-5,6,7,8-tetrahydro-2-aeetonaphthone to the haloform reaction. 

A methoxyaldehyde, m.p. 52-53°, of unassigned structure is reported in the patent literature [6] as the product from the reaction of 2-methoxy-5,6,7,8-tetrahydronaphthalene with N-methylformanilide and phosphorus oxychloride. This reaction in our hands gave a 50% yield of methoxyaldehyde (VII), m.p. 51 6-52°, whioh was oxidized with potassium permanganate in acetone solution to 3-methoxy-5,6,7,8-tetrahydro-2-naphthoic acid. The structure of the latter was established by mixture m.p. with an authentic sample prepared [7] by converting 3-hydroxy-5,6,7,8-tetrahydro-2-naphthoic acid to the... 

The starting material for the 1,2-disubstituted tetrahydro-naphthalenes was 5,6,7,8-tetrahydro-2-naphthol. This compound was converted in low yield to the known Via by the Reimer-Tiemann reaction. VI6 and Vic both were prepared from 1-bromo-2-methoxy-5,6,7,8-tetrahydronaphthalene. Although VI6 was prepared according to the method of O Farrell et al. [3], we obtained a much higher yield,... 

The reaction of methoxy-substituted 1,4-dihydroaromatic systems is a general one. Other condensed systems react in a similar manner, for example, 3,6-dimethoxy-l,4,5,8-tetrahydronaphthalene and derivatives of anthracene (35) and xanthene (36) (74). The proposed method enables synthesis of the tri-and tetracarbocyanines where the whole chromophore is integrated into a rigidizing skeleton. Asymmetrical polymethines can also be obtained similarly. 

A mixture of 61.7 g POCI, and 54.3 g N-methylformanilide was heated on the steam bath for 15 min which produced a deep red color. This was added to 54.3 g of 5-methoxy-1,2,3,4-tetrahydronaphthalene, and the mixture was heated on the steam bath for 2 h. The reaction mixture was quenched in 1.2 L H20 with very good stirring. The oils generated quickly turned to brown granular solids, which were... 

Arylacetic acids. A new synthesis of phenylacetic acids from aromatic ketones is illustrated for conversion of 6-methoxy-l-tetralone (1) into 6-methoxy-l,2,3,4-tetrahydronaphthalene-1-carboxylic acid (3). 

Methoxy-7-methoxycarbonyl-l,2,3,4-tetrahydronaphthalene 2-Naphthalene-carboxylic acid, 5,6,7,8-tetrahydro-3-methoxy-, methyl ester (10) ... 

The observations that the pH-independent reactions of deuterium-labeled 5-met-hoxyindene oxide and 6-methoxy-1,2,3,4-tetrahydronaphthalene-1,2-oxide show significant primary kinetic deuterium isotope effects for the ketone-forming reactions, whereas the pH-independent reactions of deuterium-labeled naphthalene oxide and benzene oxide do not, are quite puzzling. Clearly, more work needs to be done to fully understand why transition-state structures for rearrangement of arene oxides to phenols differ from those for rearrangement of benzylic epoxides to ketones. 

By contrast with the conditions for aldehydes, ketones have been oxidised to phenols by methodology essentially that of the cumene-hydroperoxide rearrangement. In the naphthalenic series, treatment of the derived t-alcohol shown with excess 90% hydrogen peroxide followed by stirring of the mixture with a little 4-toluenesulphonic acid for 6 hours at 22 C gave the phenolic product, 2-hydroxy-3-methoxy-5,6,7,8-tetrahydronaphthalene in 85% yield (ref.45). 

After washing the organic phase with 3x75 mL 5% NaOH, the solvent was removed under vacuum to give 48.2 g of a black residue. This was distilled at 80-100 deg C at 0.25 mm/Hg to provide 33.9 g 5-methoxy-1,2,3,4-tetrahydronaphthalene as a white oil. The NaOH washes, upon acidification and extraction with CH2CI2 gave, after removal of the solvent under vacuum and distillation of the residue at 0.35 mm/Hg, 11.4 g of recovered starting phenol. 

Carbon tetrachloride Diacetone alcohol Dibutyl ether 1,4-Dioxane Ethyl chloride Ethyl ether 2-Hexanone Isophorone Isopropyl acetate 2-Methoxy-1-propanol acetate 1-Nitropropane Paraldehyde Propylene dichloride Tetrabromoethane Tetrahydronaphthalene 1,1,2-Trichloroethane solvent, fat-soluble antioxidants Sucroglycerides Sucrose fatty acid esters solvent, fat-soluble substances pharmaceuticals Sesamol... 

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