Triethyl 7? -tartrate

Figure 9 A synthetic mixture of water-soluble carboxylic acids separated by anion-exchange chromatography. Column 0.3 cm x 300 cm Diaoion CA 08, 16-20 p (Mitsubishi Kasei Kogyo). Eluant 200 mM HC1. Detection reaction with Fe3-benzohy-droxamic acid-dicyclohexy carbodiimide-hydroxylamine perchlorate-triethyl amine with absorbance at 536 nm. Analytes (1) aspartate, (2) gluconate, (3) glucuronate, (4) pyroglutamate, (5) lactate, (6) acetate, (7) tartrate, (8) malate, (9) citrate, (10) succinate, (11) isocitrate, (12) w-butyrate, (13) a-ketoglutarate. (Reprinted with permission from Kasai, Y., Tanimura, T., and Tamura, Z., Anal. Chem., 49, 655, 1977. 1977 Analytical Chemistry).

Triethyl selenium hydroxide, (C2H5)3SeOH, is a powerful base, obtained by the action of moist silver oxide on the preceding iodide. It readily absorbs carbon dioxide. All its salts are crystalline, have a bitter taste, and all are deliquescent except the tartrate, (C2H5)3SeC4H506. 2H20, which forms delicate, pale rose-red needles. 

Diethyl L-tartrate was usually purchased from Aldrich Chemical Co., Ltd., the diester was also prepared from L-tartaric acid by the procedure of Kocienski2 (triethyl orthoformate-ethanol-acetyl chloride) or Seebach3 [ethanol-acidic ion-exchange resin (Lewatit 3333)]. 

OXIDATION, REAGENTS Barium mangan-ate. Benzyl(triethyl)ammonium permanganate. Bispyridinesilver permanganate. Bis(trimethylsilyl)peroxide. t-Butyl hydroperoxide. t-Butyl hydroperoxide-Benzyltri-methylammonium tetrabromooxomolyb-dale. t-Butyl hydroperoxide-Bisoxobis-(2,4-pentadionato)molybdenum. t-Butyl hydroperoxide-Chromium carbonyl. t-Bu-tyl hydroperoxide-Dialkyl tartrate-Titan-ium(IV) isopropoxide. t-Butyl hydroper-... 

Such experiments show that oxalate, tartrate, and citrate give fairly strong complexes, and indeed these mixtures do not suffer quite such rapid oxidation as the other systems (57, 70). Stability constants for the complexing of U(III) by acetate, 2-hydroxy-2-methylpropionate, nitriloacetate, trans-cyclohexyl-1,2-diaminotetraacetate, ethylenedi-amine tetraacetate, and diethylenetriamine pentaacetate have been reported, but no pure compounds have been isolated (71). Thiocyanate also accelerates oxidation of the uranium, but the blue complex that is formed can be extracted with triethyl phosphate, tributyl phosphate, or better, trioctyl phosphine oxide the organic extract decomposes only slowly (45, 72). 

Hypromellose phthalate can be applied to tablet surfaces using a dispersion of the micronized hypromellose phthalate powder in an aqueous dispersion of a suitable plasticizer such as triacetin, triethyl citrate, or diethyl tartrate along with a wetting agent. ... 

Fig. 22. Apparent mechanical water permeability Lp of sprayed CA latex films vs weight loss of teachable materials. Key ( ) diacetin ( ) diethyl tartrate ( ) ethylene glycol monoacetate (A) triethyl phosphate (O) trimethyl phosphate ( ) ethylene glycol diacetate + diethyl tartrate (A) ethylene glycol diacetate + trimethyl phosphate [135]...

Treating diethyl (-h )-(i ,i )-tartrate (lb) with triethyl orthoacetate under acidic conditions provides the cyclic orthoester 530, which is then ring opened with acid to afford the monoacetate 531 in 94% overall yield. Protection of the free hydroxyl group followed by basic hydrolysis of the acetate furnishes 532. The regioselective reduction of 532 with borane-dimethylsulfide complex and a catalytic amount of sodium borohydride followed by acetonide... 

Additives used in final products Plasticizers diethyl phthalate, triethyl citrate, triacetin, dibutyl tartrate, glycerol, propylene glycol, tripropionin, triacetin citrate, acetylated monoglycerides ... 

With the exception, however, of triethyl citrate, nearly all the nonvolatile esters are to a great extent removed mechanicsdly during the evaporation in the oil vapour. To detect, for example, glyceryl acetate, eth oxalate, ethyl tartrate, and ethyl succinate, the evaporation should only be proceeded with until about 10 to 15 per cent, of tRe oil is left in the dish, and this residue tested for the various acids. 

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