N-Lauroyl-L-valine

The resolution of optically active compounds by gas chromatography with chiral phases is a well-established procedure, and the separation of IV-perfluoro-acetylated amino acid ester enantiomers in 1967 was the first successful application of enantioselective gas-liquid chromatography [39] Amino acids have been resolved as their A-trifluoroacetyl esters on chiral diamide phases such as N-lauroyl-L-valine rerr-butylamide or iV-docosanoyl-L-valine fert-butylamide [40,41,... 

Of the salts of N-lauroyl-L-valine only the sodium and the potassium salts were active (Homma et al., 1973b). 

The fungicide N-lauroyl-L-valine does not pollute the environment, because the N-acyl bond of the complex is easily ruptured, and the two components are rapidly degraded by microorganisms (Misato et al., 1974). 

The magnitude of the effects reported are of the same order as those found, e.g., in the partitioning of N-acyl-a-amino acid esters between the gas phase and diamides such as N-lauroyl-L-valine t-butylamide. 

Thus, on N-lauroyl-L-valine t-butylamide, the two enantiomeric N-TFA 0-methyl esters of leucine emerge (Fig. 1) seven minutes apart, and for the iso-... 

Chromosorb W AW coated with 10% N-lauroyl-L-valine t-butyl-amide temperature, 110 C [8]... 

It has been shown in our laboratory [35] that a-amino acid derivatives, such as N-lauroyl-L-valine t-butylamide and N-TFA-val-valine-cyclohexyl ester, of 70% optical purity, could be enriched to 90-100% by chromatography on silica gel with an organic eluant in the absence of a chiral reagent (see Fig. 4). 

Figure 13.14 Some representative chiral stationary phases for gas chromatography. (I), N-lauroyl-S-a-(l-naphthyl) ethylamine (II), N-docosanoyl-L-valine-t-butylamide (III), N-trifluoroacetyl-L-valyl-valine cyclohexyl ester (IV), polymeric chiral phase prepared from polycyanopropylmethylphenylmethyl silicone and L-valine-t-butylamide.

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See also in sourсe #XX -- [ ]

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