Ketovinyl groups

Tphe presence of the ketovinyl groups has been implicated in the anti-bacterial activity of a number of substances (I), both natural and synthetic (1—7). An example is penicillic acid which exists mainly in the cyclic form (I) whereas, at higher pH, the anion of the chain form (II) occurs (6, 8). Addition to or loss of the reactive double-bond in these compounds markedly reduces their activity (I, 6, 7). The bacteriostatic... 

Meanwhile, Nikolay had started his new research on the preparation, reactions, and synthetic applications of p-chloro vinyl ketones and related compounds (p-aminovinyl ketones, p-kctoacetals). Efficient synthetic methods were developed and improved, including C-ketovinylation (introduction of the RCOCH = CH group), and a number of useful heterocyclic compounds (pyrazoles, triazoles, pyridines, and so on) were synthesized. The discovery of enamine-imine tautomerism in p-aminovinyl ketones was another remarkable achievement by Nikolay at that time. For these studies he received in 1953 the degree of Doctor of Science in chemistry. He continued as a lecturer and supervisor of postgraduates at the University, becoming docent (associate professor) in 1951 and full professor in 1955. 

It is predicted that in an acidic medium a protonated amino group will leave preferentially to many other groups. While this geminate element effect has not been investigated in such media, it is known that the salts of /3-alkylammoniumvinyl ketones are better ketovinylation reagents than /3-chlorovinyl ketones (Nesmeyanov and Rybinskaya, 1957). 

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