Phloroglucin

Resorcin2 Eine Losung von 2,3 g (14,2 mMol) Phloroglucin-Bis-hydrat in 100 ml Wasser wird unter Riihren innerhalb 30 Min. zu einer Losung von 3,1 g (82 mMol) Natriumboranat in 20 ml Wasser getropft. Manriihrt 1,5 Stdn., versetzt mit verd. Salzsaure, dampft i. Vak. ein und extrahiert den Riickstand kontinuierlich mit Benzol Ausbeute 1,4 g (90% d.Th.) F 100-107° aus Benzol F 109-110°. 

Brune A, B Schink (1990) Pyrogallol-to-phloroglucinal conversion and other hydroxyl-transfer reactions catalyzed by cell extracts of Pelobacter acidigallici. J Bacterial 172 1070-1076. 

Der daneben durch zweimalige Isobutyrylierung entstehende Di-isobutyryl-isobuttersaureester laBt sich durch Triphenyl-methyl-Natrium zu Hexamethyl-phloroglucin kondensieren ... 

Tab. 4 (S. 28) zeigt einige Beispiele fiir Azokupplungen mit Resorcin und Phloroglucin.

Tab.4 Diarylazo-Verbindungen aus Aryl-diazonium-Salzen mit Resorcin bzw. Phloroglucin... 

Dinitro-dihydroxy-azo-quinone, called by v. Herz Dinitro-3,5-di-oxy-quinone-diazide, or Dinitro-phloroglucin-diazo-anhydride... 

Nitro-Derivatives of Aryl-N-hydroxylamine 6-Nitro-2,4-Dihydroxy lamino-phloroglucinol (called -phloroglucin in Ger). (H0)3C6(N02) (NHOH)2 mw 233.14, N 18.03%, OB -58.5% yellowish needles, mp 166° (decomp) has similar props and same meth of prep as the dinitro derivative described below... 

A white, or slightly yellowish, crystalline powder, which loses its water of crystallization at 100° C., and which, on being rapidly heated, melts at 217 to 219° C., but which, when slowly heated, melts at a much lower temperature (200 to 209° C.). Phloroglucin is easily soluble in water, alcohol, and ether. 

Diresorcin. — Warm a few milligrams of phloroglucin with 1 cc. of concentrated sulphuric acid and 1 to 2 cc. of acetic anhydride for five to ten minutes in a boiling water-bath. No blue color should develop. 

Chow and Mak came to a similar conclusion on investigating the chiroptical properties of dendrimers containing enantiomerically pure threitol building blocks obtained from tartaric acid as spacers between the achiral phloroglucin branching units (see Fig. 4.73) [27]. They found that the chiral spacers in the dendrimer scaffold do not influence one another and contribute additively to the overall rotation. Moreover, they also observed that on introduction of both enantiomers one (R,R)-threitol unit precisely compensated the rotational contribution of one (S,S)-threitol unit, provided that the enantiomeric building blocks were located at equivalent positions within the dendrimer scaffold. However, CD-spectroscopic data revealed that the contribution of the exterior threitol units to the total rotation must be slightly different from that of the interior units. 

Snccino-succinic ester, like phloroglucin, exhibits dynamic isomerism (tautomerism), behaving under some conditions as a lceto-body, and under other conditions as a hydroxylic, or phenolic body having this structure ... 

Malonic ester. Phloroglucin dicarboxylio acid diethyl estei Lang, Ber., 1886, 19, 2938 see also Moore, Tram. Ghem. Boc., 1904, 85, 165. 

Lignocellulose (Lignified wall). Wo 0 d y parts of plants, such as stem cells, bast fibers, wood fibers, etc. Phloroglucin with HCl imparts a red color except to bast fibers of flax. Corallin-soda solution imparts pink color. Aniline sulphate with HjS04 colors it a golden-yellow. Chlorzinc-iodine imparts a yellow color. 

Lig nin.—A substance that adheres to the cellulose walls of certain cells and which is characterized by taking on a reddish coloration with phloroglucin and hydrochloric acid. 

At a higher temperature protocatechuic acid is formed. On reduction of quercitin the final product is phloroglucin [28]. 

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