Of orcinol

Bial s reagent (for pentoses) dissolve 1 g of orcinol in 500 mL of 30% HCl to which 30 drops of a 10% ferric chloride solution have been added. 

The intermolecular coupling of phenols is used extensively in what are believed to be biomimetic alkaloid syntheses. Aqueous solutions of iron(lll) salts are most frequently used as the oxidising agent and the dimerization process must involve phenoxy radicals. Examples are the dimerization of orcinol 21 [114] and the formation of bis-benzyltetrahydroisoquinolines 22 [115],... 

A mixture of orcinol (213, Scheme 54) and the catechol 214 on air oxidation in basic solution provides the dibenzofurantriol 216 in unspecified yield. The intermediate 215 can be isolated. ... 

The plate is finally removed, dried and sprayed with a freshly prepared solution of orcinol (0.2 g/dl) in sulphuric acid (20 g/dl). The oligosaccharide bands are then visualised by heating on a hotplate at 100°C and examined by transparency. 

B. Orcinol Monomethyl Ether. In a 1-1. three-necked flask equipped with a magnetic stirrer, a condenser, a dropping funnel, and a nitrogen inlet are placed 250 ml. of dry dimethyl-formamide (Note 6) and 22 g. (0.55 mole) of sodium hydride (60% oil dispersion). The suspension is stirred under an atmosphere of dry nitrogen and cooled with an ice bath while a solution of 31 g. (37 ml., 0.50 mole) of ethanethiol (Note 7) in 150 ml. of dry dimethylformamide (Note 6) is added slowly from the dropping funnel over a period of 20 minutes. The ice bath is removed and stirring is continued for an additional 10 minutes. A solution of 38.0 g. (36.5 ml., 0.25 mole) of orcinol dimethyl ether in 100 ml. of dry dimethylformamide (Note 6) is added in one lot, and the mixture is refluxed under an atmosphere of dry nitrogen for 3 hours (Notes 8 and 9), The mixture... 

V.p.c. analysis of the product on two columns (silicone gum rubber SE-30 and OV-1) indicated the presence of traces of two other compounds with retention times longer than that of orcinol dimethyl ether. These impurities, which were most likely C-methylated materials,2 totaled less than 0.5% of the product. 

Previous preparations of orcinol monomethyl ether have been effected by partial methylation of oricinol with methyl iodide and potassium hydroxide3 or sodium ethoxide,4 or with dimethyl sulfate and sodium hydroxide.5 These procedures required tedious purification stages and the pure monomethyl ether was obtained in 37 % yield at best.5... 

The X-ray crystal structure of A1 -tetrahydrocannabinolic acid B is reported,362 and one of the previously reported (Vol. 4, p. 75) dihydrobenzofurans from the citric acid-catalysed condensation of orcinol with menth-4-en-3-ol is shown to be (256) by X-ray analysis.363 G.c.-m.s. assay of A -THC-OMe allows the detection of 1 ng mP1 plasma of A -THC.364 The mass spectral fragmentation of A -THC, A6-THC, and some isomeric cannabinoids to the prominent m/e 231 ion has been examined.365 Miniaturized syntheses of 32 natural, or potentially natural, cannabinoids are reported in connection with their chromatographic analysis.366... 

The cleavage of S-diketo acid is commonly seen in polyphenol metabolism and degradation such as orcinol (5-methylbenzene-l,3-diol) catabolism in Pseudomonas putida. Acetylpyruvate hydrolase (ca 38 kDa) is the terminal enzyme of orcinol catabolism, catalyzing the conversion of acetylpyruvate into acetate and pyruvate (equation 12). ... 

By heating with HCl, pentoses are converted to furfural, which reacts with orcinol to form green compounds. Dissolve 300 mg of orcinol in 100 mL of concentrated HCl and... 

Orcein. A dye first prepd from lichens (cudbear, q.y., or archil). Prepn by oxidarion of orcinol with H302 in the presence of ammonia water Zulkowski, Peters, Afo. 

C-Alkylation. Grifolin (2) has been synthesized in 15% yield by the reaction of orcinol (1, excess) with farnesyl bromide in dry dioxane containing silver oxide. Some of the 4-farnesyl isomer is formed as well. The reaction of orcinol... 

Podlech et al. recently reported on a total synthesis of alternariol (732) with a palladium-catalyzed Suzuki-tyipe coupling as the key reaction 495). The synthesis began by preparing the orcinol-derived boronic acid 748 by methylation and subsequent bromination with iV-bromosuccinimide (NBS) of orcinol 746 362), and treatment of 747 with butyUithium, followed by forming the boronic acid with tri/so-propyl borate (496) (Scheme 11.2). The brominated Suzukt-coupling partner was achieved by a Vilsmeyer formylation of 3,5-dimethoxybromobenzene (749) (497), which was further oxidized under Kraus conditions (242) and esterified to obtain the methyl ester 751. 

Birch AJ, Donovan FW (1953) Studies in Relation to Biosynthesis. I. Some Possible Routes to Derivatives of Orcinol and Phloroglucinol. Aust J Chem 6 360... 

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