Ethanol Specifications

Reduction. PMHS and an organotin catalyst, bis(dibutylacetoxytin)oxide (UBATO), in a refluxing protic solvent (usually ethanol) specifically reduce aldehydes and ketones to alcohols in high yield. One equivalent of siloxane hydride is required per mole of substrate with the solvent contributing a proton ... 

Procedures for the extraction of carotenoids from a wide variety of tissues have been reported in the literature. Because of differences in plant materials, no one method can be considered universal. However, the various methods are quite similar in principle. Carotenoids are extracted with an organic solvent such as methanol, ethanol, acetone, hexane, or petroleum ether. These may be used singly or as mixtures of two or more. In some cases, heating has been used to facilitate the extraction, although there is some risk in this as noted above. Grinding or blending has been used with some tissues, and in some cases this has been carried out with the solvent directly. When extracting fresh tissue, the initial extraction must be carried out with a water-miscible solvent such as acetone, methanol, or ethanol. Specific examples of procedures for various tissues are discussed in the review by Davies (1976). 

The appearance of the amino group can be measured by its reaction with nitrous acid, reaction with ninhydrin (colorimetrically or gasometrically), titration in acetone, and titration in the presence of formaldehyde. The appearance of a carboxyl group can be measured by titration in ethanol. Specific methods can be used for the determination of certain amino acids when these are liberated by hydrolysis. 

Self-catalyzed transesterification with 2-dimethylaminoethanol in DMF has been found effective in cleaving protected peptides from the Mer-rifield resin, in the absence of side-chain benzyl ester protecting groups (Barton et al., 1973). This mild, virtually racemization-free procedure may prove extremely useful for fragment condensation because it yields N-Z-and iV-Boc-protected peptides. Since the reagent, 2-dimethyl-amino-ethanol, specifically cleaves of the benzylic ester group, the benzyl esters of glutamic acid and aspartic acid, if present, will also be hydrolyzed (Barton et al., 1973 Savoie and Barton, 1974). 

In reviewing the fiiU range of health and safety issues associated with all alternative fuels, the California Advisory Board determined that there were no roadblocks that would prevent the near term deployment of either methanol or ethanol, assuming that adequate safety practices were foUowed appropriate to the specific nature of each fuel (14). 

Alcoholic Fermentation. Certain types of starchy biomass such as com and high sugar crops are readily converted to ethanol under anaerobic fermentation conditions ia the presence of specific yeasts Saccharomyces cerevisia and other organisms (Fig. 6). However, alcohoHc fermentation of other types of biomass, such as wood and municipal wastes that contain high concentrations of cellulose, can be performed ia high yield only after the ceUulosics are converted to sugar concentrates by acid- or enzyme-catalyzed hydrolysis ... 

The Diabrotica spp. com rootworm beetles are specifically attracted to a variety of plant-produced phenylpropanoids, eg, ( )-cinnamaldehyde [14371-10-9] for the southern com rootworm D. undecimpunctata howardr, ( )-cinnamyl alcohol [4407-36-7] for the northern com rootworm D. barberi and indole [120-72-9] for the western com rootworm, D. virgifera virgifera. Especially powerflil lures for these rootworm beetles are 2-(4-methoxyphenyl)ethanol for the northern com rootworm and 4-methoxycinnamaldehyde [71277-11-7] (177) for the western com bootworm. 

The advent of a large international trade in methanol as a chemical feedstock has prompted additional purchase specifications, depending on the end user. Chlorides, which would be potential contaminants from seawater during ocean transport, are common downstream catalyst poisons likely to be excluded. Limitations on iron and sulfur can similarly be expected. Some users are sensitive to specific by-products for a variety of reasons. Eor example, alkaline compounds neutralize MTBE catalysts, and ethanol causes objectionable propionic acid formation in the carbonylation of methanol to acetic acid. Very high purity methanol is available from reagent vendors for small-scale electronic and pharmaceutical appHcations. 

The normal salt, CH COONH, is a white, deUquescent, crystalline soHd, formula wt 77.08, having a specific gravity of 1.073. It is quite soluble in water or ethanol 148 g dissolve in 100 g of water at 4°C. The salt s solubiUty in water increases only slightly as temperature increases up to about 25 °C. The specific gravity of aqueous neutral ammonium acetate ranges from 1.022 to 1.092 as solution concentration increases from 10 to 50 wt % (4). The normal salt melts at 114°C, but decomposes before reaching its boiling point. 

To illustrate the use of these equations, consider a charge of 520 mol of an ethanol-water mixture containing 18 mole percent ethanol to be distilled at 101.3 kPa (1 atm). Vaporization rate is 75 moFh, and the product specification is 80 mole percent ethanol. Let L/V = 0.75, corresponding to a reflux ratio R = 3.0. If the system has seven theo-... 

---