N-Butanoic acid

The elimination of the original CHj group from ionized n-butanoic acid, 38, was shown to proceed also mainly via a two-step process. The reaction is initiated by a hydrogen migration via a four-membered transition state 38->39, which... 

Quantification of the separated amino acids is usually performed by using external calibration or the internal standard method. Due to the large differences in chemical structure exhibited by the various amino acids, there is not a single ideal standard for the overall amino acid profile. Nevertheless, a suitable internal standard must be stable to hydrolysis and offer chromatographic resolution. The most popular choices comprise norleucine, norvaline, and a-amino-n-butanoic acid (AABA) [196]. 

Since no single internal standard can possibly mimic the chemistry of all the amino acids (for overall profile), the choice of internal standard has been based primarily on two criteria. The first is chemical stability. The internal standard must not be labile under the conditions employed. The second is that the internal standard must offer chromatographic resolution. This is not easy, since the overall profile produces a chromatogram that is already very cluttered. A review of the literature reveals that three internal standards are the overwhelming popular choices norleucine, norvaline, and a-amino-n-butanoic acid (AABA). It should be noted that norleucine and norva-line are very hydrophobic amino acids, whereas AABA is relatively hydrophilic. How these standards might behave during sample preparation steps (e.g., filtration) as a function of their hy-drophobicity should be taken into consideration. 

That unactivated carbon-dn bonds could be oxidized direedy in a potentially useful synthetic way was demonstrated in 1964. Symmetrical tetraalkylstannanes reacted with chromic anhydride (CrOs) in acetic acid to yield aldehydes and acids depending on the conditions (equation 1). Using a large excess of oxidant (12-fold excess) and long reaction times (360 h at 20 C) a near quantitative yield of n-butanoic acid was obtained from Bu"4Sn. ... 

Saturated Fatty Acids Butyric acid C4 0 n-Butanoic acid... 

CAS Synonyms (Copyright 1987 by the American Chemical Society) n-Butanoic acid n-Butyric acid Butyric acid Ethylacetic acid 1-Propanecarboxylic acid Propylformic acid Butyrate... 

Butanic acid. See n-Butyric acid Butanimide. SeeSuccinimide Butanoic acid n-Butanoic acid. See n-Butyric acid... 

CAS 107-92-6 EINECS/ELINCS 203-532-3 UN 2820 (DOT) FEMA 2221 Synonyms Butanic acid Butanoic acid n-Butanoic acid Carboxylic acid C4 Ethylacetic acid... 

Acetic acid is both a reactant and solvent in the manufacture of cellulose acetate, polyester fibers, and plastics. Other products that utilize acetic acid as a reactant include vinyl acetate, ester solvents, dyes, metallic salts, pharmaceuticals, and pesticides. Formic acid is used in textile dyeing and finishing, leather tanning and treatment, pharmaceuticals, and the synthesis of the versatile methyl formate solvent. n-Butanoic acid is used in the preparation of cellulose acetate butyrates used for lacquers and molding plastic compositions. The acid is also used for the production of useful coating ester solvents, plasticizers, and pharmaceuticals. 

Figure 23.31 (a) Structures of kahalalides A-J. Bu, n-butanoic acid 2-MeBu, 2-methylbutanoic acid Zdhb, Z-dehydroaminobutyric acid 4-hypro,... 

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