Naphthol 5,8-dihydro

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%). ... 

Dihydro-1 -naphthol Silver acetate Sodium hydroxide Epichlorohydrin... 

Partial reduction of naphthols was accomplished by sodium in liquid ammonia. In the absence of alcohols small amounts of 5,8-dihydro-a-naphthol or 5,8-dihydro- -naphthol were isolated. In the presence of tert-amyl alcohol, a-naphthol gave 65-85% yield of 5,8-dihydro-a-naphthol while -naphthol afforded 55-65% of -tetralone [399] Procedure 26, p. 211). Lith-... 

Oder 4) bzir. 4 Nitroao-6.8(odar 7.8)-dihydro-naphthol-(l) 7 II635. 6.8-Dmydro-aaphthocliinon-(l. 4)-monoxini bzw. 4-Xitioso-5.8-dihydro-naphthol-(l)... 

Dienes can also be used ia Friedel-Crafts cyclo alkylations. For example, treatment of phenol with 2,5-dimethyl-2,4 hexadiene gives 5,5,8,8-tetramethyl,6,7-dihydro-2-naphthol. 

Substituted amino naphthols were synthesized with reactions of 1-naphthols and the appropriate aldehydes. Some new 2,4-disubstituted-3,4-dihydro-2/f-naphth [i,2-e][i,i]oxazines that are expected to show biological activities were obtained by the ring-closure reactions with these aminonaphthols and various aldehydes. In addition, substituted-1,3-amino-hydroxy compounds, 2, can be used in chiral ligands synthesis. 

Biological. In activated sludge, 9.0% of the applied amount mineralized to carbon dioxide after 5 d (Freitag et al, 1985). Under certain conditions. Pseudomonas oxidized naphthalene to cis-1,2-dihydro-1,2-dihydroxynaphthalene (Dagley, 1972). This metabolite may be oxidized by Pseudomonasputida to carbon dioxide and water (Jerina et ah, 1971). Under aerobic conditions, Cunninghamella elegans degraded naphthalene to 1-naphthol, 2-naphthol, trans-l, 2-A hyAxoxy-... 

Uses Intermediate for phthalic anhydride, naphthol, 1,4-naphthoquinone, 1,4-dihydro-naphthalene, 1,2,3,4-tetrahydronaphthalene (tetralin), decahydronaphthalene (decalin), 1-nitro-naphthalene, halogenated naphthalenes, naphthol derivatives, dyes, explosives mothballs manufacturing preparation of pesticides, fungicides, detergents and wetting agents, synthetic resins, celluloids, and lubricants synthetic tanning preservative emulsion breakers scintillation counters smokeless powders. 

Methylbutyl acetate, see sec-Amyl acetate 3-Methylbutyl acetate, see Isoamyl acetate 3-Methyl-l-butyl acetate, see Isoamyl acetate 3-Methylbutyl ethanoate, see Isoamyl acetate Methylbutyl ethyl ketone, see 5-Methyl-3-heptanone Methyl n-butyl ketone, see 2-Hexanone Methylcarbamate-l-naphthalenol, see Carbaryl Methylcarbamate-l -naphthol, see Carbaryl Methyl carbamic acid, 2,3-dihydro-2,2-dimethyl-7-... 

Consecutive condensations of 2-naphthol, allylamine, and dibromomethane comprised another route to naphthalene-condensed 1,3-oxazines. A preheated mixture of allylamine and dibromomethane was reacted with 2-naphthol 152 to yield the aminophenol intermediate 520, which was cyclized with the salt formed in the reaction of dibromomethane and diethylamine to give 3-allyl-3,4-dihydro-2//-naphth[l,2-< ][l,3]oxazine 521 on further reaction (Scheme 98) <2004SC2253>. 

Condensation of 7-methoxy-3,4-dihydro-1(2H)-naphthal-enone with tetramethylene dibromide by means of NaH in benzene or tert amyl alcohol gives 3,4-dihydro-7-methoxy-2,2-tetramethylene-1(2H)-naphthalene (bp (0,05 mbar) 120-123 °C), which is treated with acetonitrile and butyllithium in THF yielding 1-hydroxy-7-methoxy-1,2,3,4-tetrahydro-2,2-tetramethylene-1-naphthalene-acetonitrile (mp 140-142 °C). This compound is reduced with LiAIH4 in THF to afford hydro-2,2-tetramethylene-1-naphthol (mp 178-180 °C), and isomerized to 4a-(2-aminoethyl)-1,2,3,4,4a,9-hexahydro-6-methoxy-phenantrene i (mp 187 °C). 

Further bromination of 3,4,6-tribromo-5-hydroxybenzo[6]thio-phene affords the 2,3,4,6-tetrabromo derivative in the absence of acetate ion, and 3,4,4,6-tetrabromo-4,5-dihydrobenzo[6]thiophen-5-one in the presence of acetate ion. 421 On treatment of 3,4-dibromo-, 4,6-dibromo-, 3,4,6-tribromo-, or 2,3,4,6-tetrabromo-5-hydroxybenzo-[6]thiophene with nitric acid in acetic acid, the corresponding unstable orange crystalline 4-bromo-4-nitro-4,5-dihydrobenzo[6]thio-phen-5-one is obtained.152,421 Hence, once both positions ortho to the hydroxyl group in 5-hydroxybenzo[6]thiophene are occupied by bromine, the properties of these compounds are analogous to the properties of l-bromo-2-naphthol which, on bromination in acetic acid in the presence of acetate ion, affords l,l-dibromo-l,2-dihydro-naphthalen-2-one whereas, in its absence, it affords l,6-dibromo-2-naphthol.616 The behavior of l-bromo-2-naphthol and its derivatives on nitration is similar to that of 4,0-dibromo-5-hydroxybenzo[6]thio-phene and its derivatives.162,616... 

On solvolysis, 1 gives three products 9-phenanthrol and cis- and trans-9,10-dihydro-9,10-dihydroxyphenanthrene.88 On the other hand, 47 and 48 give mainly 1-phenanthrol and 4-phenanthrol, respectively, along with minor amounts (3-24%) of other isomeric phenanthrols.89 Similarly, 86 gives phenol and 45 gives only 1-naphthol.90 However, in acid approximately 10% of 2-naphthol is formed. In all of the latter cases there is no evidence for the formation of dihydrodiols. 

Table 2 summarizes pK measurements for the simplest protonated aromatic hydrocarbons. The columns to the right and left of the benzenonium ion correspond to benzoannelation of ions subject to protonation at the 2- and 4-positions of the benzene ring, respectively. In the parent ion the two positions correspond to resonance forms (one of which has been rotated through 120° in the table). The naphthalenonium ion 17 is shown as being formed from the 1,4-water adduct (hydrate) of naphthalene. It may also be formed from the isomeric 2,1 hydrate (l,2-dihydro-2-naphthol) with pAR = -6.7 and pAn2o = 13.7. 

The first synthesis of (R)-4,5-dihydro-37/-dinaphtho[2,l-f l, 2 -i ]selenepin oxide 110 has been achieved from (R)-(+)-l,l -bi-2-naphthol, which in turn was obtained by resolution of raol,l -bi-2-naphthol. Palladium-catalyzed alkoxy carbonylation of the alcohol 108 gave a dimethyl ester which was then reduced by LiAlfLi, and the resultant diol converted to key intermediate chloride 109. Cyclization with sodium selenide gave a novel enantiomerically pure selenide, which upon oxidation yielded the desired selenoxide 110 <2000SC2975>. 

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