Tetramethyl Ethers

6-Tetramethyl-D-glucose is frequently isolated after hydrolysis of the methyl ethers of naturally-occurring glucose polymers (e.g. maltose, 

The Physical Properties of 2,8,4,6-Telramethyl-D-glucose and Some of Its Derivatives 

Compound Melting point, °C. [or]D Rotation solvent References 

D-glucose and its lactone from 2,3,6-trimethyl-D-glucose provided conclusive proof that the ring system was not of the hexylene oxide type.142 188 The final evidence necessary to characterize the tetramethylglucose in question as a furanose derivative was provided by Haworth, Hirst and Miller,176 who demonstrated that oxidation of the tetramethylglucose with bromine water and of the resulting lactone with nitric acid yielded dimethoxysuccinic acid and oxalic acid, but not i-zyZo-trimethoxyglutaric acid, the absence of which ruled out a pyranose structure. 

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Many novel small molecule perfluoropolyethers have been made usiag direct fluofination technology. For example, even branched ethers such as perfluoro(pentaerythritol tetramethyl ether) can be prepared ... 

Pyridone also catalyzes epimerization of the anomeric position of the tetramethyl ether of glucose. The mechanism involves two double proton transfers. The first leads to a ring-opened intermediate, and the second results in ring closure to the isomerized product ... 

The tetramethyl ether (15) mentioned above was also converted to its equatorial monobenzoate (16), and the latter methylated and de-esterified to give a hexol pentamethyl ether. As benzoyl migration occurred during methylation, this pentamethyl ether had the configuration 18, and was not the diastereomer (19) mentioned above (27). 

Gossypetin, 3-7-di-O-methyl lLTOOS Gossypetin-3-3 -7-8-tetramethyl ether Guaiacin, didehydro, 3 -3 -demethoxy-6-0-demethyl Lf/Tw 2.8 ° ... 

Wollenweber, E., Mann, K., and Roitman, J.N., A myricetin tetramethyl ether from the leaf and stem surface of Tillandsia usneoides, Z. Naturforsch., 47c, 638, 1992. 

Hydroxyluteolin 5,6,3, 4 -tetramethyl ether 7- Cellobioside Sphaeranthus indicus stems Compositae 136... 

Tricetin 7,3, 4, 5 -tetramethyl ether 5-Glucoside Lethedon tannaensis leaves Thymelaeaceae 126... 

FFydroxytricetin 6,7,3, 5 -tetramethyl ether 5-Robinobioside Aloe barbadensis leaves Liliaceae 155... 

Hydroxykaempferol 3,5,7,4 -tetramethyl ether 6-Rhamnoside Pterocarpus marsupium roots Leguminosae 300... 

Quercetin 5,7,3, 4 -tetramethyl ether 3-Galactoside Sesbania aculeata Leguminosae 410... 

When hydride ion is used as the nucleophile, the product is unsubstituted at C-4. Thus, luteolinidin tetramethyl ether (182) affords the flavene (equation 4) (58JCS4040). 

Fig. 15. Kinetics [59] of dark recombination of the (ZnP1 - CC14 ) pairs in the illuminated vitreous solution of tetramethyl ether of zinc hemato-IX porphyrin (ZnP, N 10 5M) in ethanol containing CC14 in various concentrations , 0.5M O, 1M +, 1.5M and V, 2M.

Fig. 18. The kinetics [63] of the phosphorescence decay of tetramethyl ether of copper hemato-IX porphyrin (CuP) in the presence of various concentrations of C(N02)4 1, 0 M 2, 0.3 M and 3, 0.6 M. The points represent the experiment and the solid lines reflect the calculation using eqn. (12) of Chap. 7.

Parameter Copper tetra-phenylporphin Copper tetra-phenyl(pival-amido) porphin Tetramethyl ether of copper hemato-IX porphyrin... 

Purpurogallin tetramethyl ether (Formula 25) gives Formula 26 on irradiation in ethanol (17). The formation of the methyl ester in ethanol... 

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