2-Oxo-3-methylvaleric acid

The commonly used derivatives for oxo acids, the TMS-oxime, form single peaks for most acids as shown in Fig. 4.3 (Stemowsky et al., 1973) with the exception of 2-oxo-3-methylvaleric which gives a doublet arising from the D and L forms. Fortunately the D-form is not naturally occurring in physiological fluids. The retention times of the TMS-oxime-TMS-ester derivatives are... 

Fig. 4.3 Chromatogram of standard oxo acids separated as their trimethysilyl-oxime derivatives on 3 per cent OV-17 using temperature programming from 110°C to 220°C. Peak identifications are 1, pyruvate 2, 2-oxobutyrate 3, 2-oxoisovalerate 4, 2-0X0valerate 5, L-2-oxo-3-methylvalerate 6, 2-oxoisocaproate plus 7, d-2-oxo-3-methylvalerate 8, 2-oxo-4-methylthiobutyrate 9, 2-oxoglutarate 10, phenylpyruvate. (Redrawn with modifications from Sternowsky etal., 1973)...

Ethyl 2-amino-2-cyanoacetate (282) and 2-hydroxyimino-4-methylvaleric acid (283) gave ethyl 3-amino-5-isobutyl-6-oxo-l,6-dihydro-2-pyrazinecarboxy-late 4-oxide (284) (N,N -dicyclohexylcarbctdiimide %).1259... 

I( 3-nu thyl-l-oxo.2-phenylpen tvl)oxy]etha no minium bromide 3-methyl-2-phenylvaleric acid diethylO-hydroxyethyli-melliylonirnonium bromide ester 2-phenyl-3-methylvaleric add (J-(diethylamino)ethyl ester bromomethylate 3-methyl -... 

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