1,4-Dihydroxy-2-naphthoic

Menaquinone. The incorporation of [2- C]mevalonate and [2- C]-2-methyl-l,4-naphthoquinone into MK-4, normally considered a bacterial quinone, has been demonstrated in marine invertebrates such as crabs and starfish." Incorporation into 2,3-epoxy-MK-4 (163) was also observed. Cell-free extracts have been prepared from Escherichia coli which catalyse the conversion of o-succinylbenzoic acid (164) into l,4-dihydroxy-2-naphthoic acid (165) and menaquinones. In the presence of farnesyl pyrophosphate the major menaquinone produced was MK-3. Genetic studies with mutants of E. coli K12 that require (164) offer support for the generally accepted pathway for MK biosynthesis via (164) and (165)." The enzyme system that catalyses the attachment of the polyprenyl side-chain to 1,4-dihydroxy-2-naphthoic acid to form demethylmenaquinone-9 (166) has been isolated from E. colU ... 

When [l-carboxy- C]o-succinyl benzoate is administered to plants of Catalpa ovata (Bignoniaceae), it is incorporated into a-lapachones (such as 45), catalponol (46), and catalpalactone (47). Examination of the ratio in catalponol (46) after administration of [l-carboxy- C,2 - H2]o-succinylbenzoate reveals that the two protons at the 2 -posi-tion are both retained in the 3-position of catalponol (Fig. 6.9). Thus, prenylation occurs at the 2-position and does not involve an aromatic compound such as 1,4-dihydroxy-2-naphthoic acid (DHNA) (40) (Inouye and Leistner, 1988). 2-Carboxy-4-oxotetralone (COT) (43) or 2-carboxy-4-hy-droxy-l-tetralone (48) are possible acceptors for the prenyl unit. When 2-carboxy-4-hydroxy-l-tetralone (48), or its methyl ester, was introduced into the plant, the prenyl derivatives of 2-carboxy-4-oxotetralone (COT) (43) and 2-car-boxy-4-hydroxy-l-tetralone (50) were isolated as intermediates (Inouye and Leistner, 1988). 

The enzymic conversion of o-succinylbenzoic acid (II) to 1,4-dihydroxy-2-naphthoic acid (DHNA) (V) is a reaction dependent on ATP, Mg + and coenz3nne A. The product DHNA is a precursor of vitamin K2. One may assume that both carboxyl groups in OSB (II) are activated during the conversion to DHNA (V). Activation of the "aliphatic" group would provide for the acidity of a proton on the methylene group... 

One of the open questions in anthraquinone biosynthesis is the nature of the branching compound X (Fig. 4). In vitamin K2 biosynthesis 1,4-dihydroxy-2 naphthoic acid (V) is involved (vide supra). It may also be an intermediate in phylloquinone s and anthraquinone biosynthesis. Feeding experiments established that anthraquinones in Rubia, Morinda and Galium >28,2 9 derived from shikimic acid, a-ketoglutaric acid and mevalonic acid with -succinylben-zoic acid being a key intermediate. Incorpo-... 

While the biosynthesis of vitamin Ki (phylloquinone) may proceed through 1,4-dihydroxy-2-naphthoic acid (DHNA) (V), > 9 an alternative route has been suggested (Fig. 

At present it is unclear whether 2-carboxy-2,3-dihydro-1,4-naphthoquinone (XXV) or 1,4-dihydroxy-2-naphthoic acid (V) or both are intermediates in the biosynthetic pathway depicted in Figure 7. Another interesting aspect of the proposed pathway (Fig. 7) is that... 

An example of a biological electrophilic aromatic substitution occurs during the biosynthesis of phylloquinone, or vitamin Kj, the human bloodclotting factor. Phylloquinone is formed by reaction of 1,4-dihydroxy-naphthoic acid with phytyl diphosphate. Phytyl diphosphate first dissociates to a resonance-stabilized allylic carbocation, which then substitutes onto the aromatic ring in the typical way. Several further transformations lead to phylloquinone (Figure 9.15). 

Animals caimot synthesize the naphthoquinone ring of vitamin K, but necessary quantities are obtained by ingestion and from manufacture by intestinal flora. In plants and bacteria, the desired naphthoquinone ring is synthesized from 2-oxoglutaric acid (12) and shikimic acid (13) (71,72). Chorismic acid (14) reacts with a putative succinic semialdehyde TPP anion to form o-succinyl benzoic acid (73,74). In a second step, ortho-succmY benzoic acid is converted to the key intermediate, l,4-dihydroxy-2-naphthoic acid. Prenylation with phytyl pyrophosphate is followed by decarboxylation and methylation to complete the biosynthesis (75). 

Biological. Catechol is the central metabolite in the bacterial degradation of phenanthrene. Intermediate by-products include l-hydroxy-2-naphthoic acid, 1,2-dihydroxynaphthalene, and salicylic acid (Chapman, 1972 Hou, 1982). It was reported that Beijerinckia, under aerobic conditions, degraded phenanthrene to as-3,4-dihydroxy-3,4-dihydrophenanthracene (Kobayashi and Rittman, 1982). 

C. 1,3-Dihydroxy-2-naphthoic acid. In a 1-1. three-necked, round-bottomed flask, fitted with a mechanical stirrer, nitrogen inlet tube, and a condenser carrying a separatory funnel attached by means of a notched cork, is placed 20.9 g. (0.09 mole) of the... 

Beginning with l,4-dihydroxy-2-naphthoic acid the preparation of the Step 1 reagent is described by the author. 

The synthesis started from commercially available 3,5-dihydroxy-2-naphthoic acid (A), which was converted to lactonic naphthoquinone B. Diels-Alder reaction of B with diene C gave a 1 1 mixture of the... 

DeCA METHYLENE BROMIDE, 20, 24 Decamethylenediamine, 27,18 Decamethylene glycol, 20, 25 1,10-Decanediamine, 27,18 Decane, 1,10-dibromo-, 20, 24 Decarboxylation, 23, 18 of l,3-dihydroxy-2-naphthoic acid, 25, 75... 

Since 1991 Kricheldorf has published many other articles on liquid crystal polyesterimides. These include two series of thermotropic copoly(esterimides) derived from N-(3 -hydroxyphenyl)trimellitimide and 4-hydroxybenzoic acid or 6-hydroxy-2-naphthoic acid, in which the critical compositions for obtaining mesophases were discovered by varying monomer levels [34]. A series of homopoly(esterimide)s were synthesised from N-(4-carboxyphenyl)trimelliti-mide and various diacetylated linked diphenols. When the diphenol contained an ether or carbonyl linking group, mobile nematic phases were observed. Various naphthalene diols were also employed instead of the diphenol, but only the 2,7-dihydroxy naphthalene produced a nematic phase [35]. 

The effectiveness of 2,6-naphthalene moiety in depressing melting temperature is also demonstrated by copolymers containing 2,6-dioxynaphthalene or 2,6-naphthoyl units. It was reported, e.g., the melting point of the polymer of terephthalic acid and 2,6-dihydroxynaphthalene was only 210 °C (Harris, 1981) that of the copolymer of 2 mol 4-hydroxybenzoic acid with 1 mol of 2,6-dihydroxy-naphthalene and 1 mol of terephthalic acid was 285 (Calundann, 1980) that of the copolymer of 1 mol hydroquinone, lmol of 2,6-naphthoic acid and 3 mol 4-hydroxybenzoic acid was 325 °C-340 °C and that of 1 mol 2,6-naphthoic acid, 1 mol 4,4 -dihydroxybiphenyl, 3mol 4-hydroxybenzoic acid was 385°C-390°C (Calundann, 1978). 

Dihydrofuro[2,3-b]naphthols, derived from 3,7-dihydroxy-2-naphthoic acids are sources of hetero-fused naphtho[2,l-b]pyrans through reaction with propynols. The oxacyclic substituent is equivalent to an alkoxy group and in the only data provided, the /-fused dihydrofuran derivative 45 exhibits a 9 nm red shift to 481 nm compared with the 8-methoxy analogue 46 <99WOP24438>. 

For the 3,3 -dimethyl derivative 8, several other methods have been developed. The racemic 3,3 -dimethy] compound can be prepared by aminomcthylation of binaphthol with subsequent conversion of the aminomethy] function to a methyl group, and resolved analogously to binaphthol via the phosphoric acid derivative15. Another possibility is the preparation [oxidation of 3-hydroxy-2-naphthoic acid with iron(III) chloride] and resolution [with (S)-leucine methyl ester] of 2,2 -dihydroxy-1,l -binaphthyl-3,3 -dicarboxylic acid (7). 

Biosynthesis. The asymmetric incorporation of 4-(2 -carboxyphenyl-4-oxobu-tyrate [o-succinylbenzoate (211)] into phylloquinone by Zea mays has been reported. The incorporation of (211), via its coenzyme A thioester, into l,4-dihydroxy-2-naphthoic acid (212) and menaquinone has been studied in cell-free extracts of Mycobacterium phlei and Micrococcus luteus. The biosynthesis and metabolism of menaquinone-4 in the crab has been described. A soluble enzyme complex capable of converting 2-octaprenylphenol (213) into... 

Dihydroxy-2-naphthoic Acid. Yellowish plates from EtOH.Aq. M.p. 220° decomp. Sol. EtOH, EtjO, Me,CO Spar. sol. CHClg, CgHg, H.O. Reduces AgNOg... 

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