A-Acetyl-mucronine

A/,A/-Dimethyl-dihydro-mucronine-F = A/-Methyl-dihydro-mucronine-E 132) A/-Acetyl-mucronine-F 132)... 

The isolation of pure bases by repeated chromatography with varied solvent systems is often tedious and sometimes not possible for example, zizyphine-B and zizyphine-C showed identical Rt values in a dozen different solvent systems. The isolation of pure zizyphine-C was only achieved when the contaminant zizyphine-B was acetylated (29). Similarly, the sensitive mucronine-G and mucronine-H were only obtained pure as acetyl derivatives (28). Presumably, the problem of the separation of these alkaloids could be rendered more facile by the high pressure liquid chromatographic technique. 

Scheme IV. Mass spectrometric fragmentation of Mucronine-A W-acetyl derivatives...

Same derivatives of a number of mucronines and abyssenines were not accessible (Section IV, E). Mass spectra of the substituted N-acetylaminoaldehydes resemble those of the acetylated alkaloids even... 

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