TETRAHYDRO-a-NAPHTHOL

Silicic acid, tetrabutyl ester 9727 Sulfanilic acid 253 1,2,3,4-Tetrahydro-a-naphthol 9875... 

Silicic acid, tetrakis(2-ethylbutyl) ester 9814 /j-Sulfanilyl fluoride 254 5,6,7,8-Tetrahydro-a-naphthol 9876... 

A chiral hydride complex, tentatively assumed to be 86, prepared by partially reacting LAH with (- )-N-methylephedrine (1 equivalent) and /V-ethylaniline (2 equivalents) was found to reduce 2-acetyl-5,8-dimethoxy-3,4-dihydronaphtha-lene (87) quantitatively to the (- )-carbinol (88) with 92% e.e. (94,95). Carbinol 88, which was obtained optically pure by recrystallization, could be converted to (/ )-(-)-2-acetyl-5,8-dimethoxy-l,2,3,4-tetrahydro-2-naphthol (89). The lat-... 

Very few physical measurements have been performed on tetrahydronaphthalene with a view to establishing the bond structure of its aromatic ring. The dipole moment measurements on 2,3-dibromo-5,6,7,8-tetrahydronaphthalene [4] have not been interpreted satisfactorily. However, Arnold and Evans [5] have shown that the acidities of 6-nitro- 3,4-xylenol, 6-nitro-5-indanol, and 3-nitro-5,6,7,8-tetrahydro-2-naphthol are virtually the same. Hence, the aromatic bonds in question in all three compounds must have nearly identical double-bond character, thus precluding any appreciable Mills-Nixon effect. 

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,... 

Eydroxy-5,6,7,8-tetrahydro-l-napMhaldehyde was prepared [7] by the Reimer-Tiemann reaction cn 5,6,7,8-tetrahydro- 2-naphthol. Three recrystallizations from aqueous alcohol afforded a very low yield of pure aldehyde, m.p. 86-8-87-8° (spectral sample) lit. m.p. 86-87° [7J. 

A method employing a similar effect is that of Windaus, Weinhold, and Klanhardt,87 who found that digitonin precipitates the digitonide of one (partially) active form of a-terpineol and oc-tetrahydro-/3-naphthol when added to a solution of the racemic form. The method failed with dt-carvomenthol and eM-methylphenylcarbinol and with the majority of... 

In compounds with both saturated and aromatic rings, the former appears to be the most readily hydroxylated. For example, the major oxidation products of tetralin (5,6,7,8-tetrahydronaphthalene) in the rabbit are 1- and 2-tetralol, whereas only a trace of the phenol, 5,6,7,8-tetrahydro-2-naphthol, is formed (Figure 10.1D). 

The reaction may also be performed over a mixed-oxide catalyst at 280° and 100 atm. of ethylene, which serves as the hydrogen acceptor, as illustrated by the preparation of /3-tetralone from 1,2,3,4-tetrahydro-2-naphthol. By the same procedure, diisobutyryl, a diketone, has been prepared from the acyloin (27%). ... 

R) -( + )-2-Acetyl-5,8-dimethoxy-l,2,3,4-tetrahydro-2-naphthol (173) is a key intermediate in the asymmetric synthesis of anthracycline antitumor agents demethoxyadriamycin (174 X = Y = OH) and 4-demethoxydaunomycin (174 X = Y = H) <94JOCli84>. The crucial step in a highly efficient asymmetric synthesis of (173) involves the enantioselective hydroxylation (>95% ee) of the potassium enolate of (171) with (—)-[(8,8-dimethoxycamphoryl)sulfonyl]-oxaziridine (158) to afford (172). Conversion to (173) was accomplished in three steps in 50% overall yield from (171) without racemization (Scheme 32). 

Reduction of a-naphthol by the Wilds-Nelson technique to 5,8-dihydro-1-naphthol is the first step in a procedure for the preparation of or-tetrahydro-l-naphthol (overall yield 84-88%). ... 

This chapter describes our recent advances on the utilization of polymer-modified laccase complexes in aqueous systems towards the oxidation/polymerization of naturally hydro-phobic steroidal compounds, Equilin (EQ) and 17-P-estradiol (P-EST). We elucidate the kinetic and synthetic aspects of the process with the model compoimd 5,6,7,8-tetrahydro-2-naphthol (THN). The nano-reactor system is composed of linear poly(ethylene oxide)-dendritic poly(benzyl ether) diblock copolymer (G3-PE013k) and laccase isolated from Trametes versicolor. Other advantages of the complex in comparison to the native enzyme are its recyclability, enhanced stability, activity, and overall simplicity in product harvesting and isolation. A principle of action of the complex is suggested based on these findings and is further supported by the biphasic solid-liquid nature of the reaction medium, which exhibits continuous influx of starting material and steady solid product expulsion. Comparative experiments with linear-linear poly(styrene)-Woc -poly(ethylene oxide) copolymer under identical conditions do not evince formation of a... 

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