The nucleophilic ring opening of donor-acceptor cyclopropanes with the cyanate ion is reported for the first time. Cyclopropanes, spiro-activated with oxindole fragments as acceptors, are shown to undergo transformations into biologically relevant spiro[pyrrolidone-3,3'-oxindoles] while being treated with potassium cyanate under microwave assistance.

A new synthetic approach to functionalized quinolines was developed based on the application of Zn–AcOH system as a simple and efficient reductive agent towards 4‐(o‐nitroaryl)‐3‐acyl‐substituted 4,5‐dihydrofurans. Reduction of 3‐carbonyl‐substituted dihydrofurans is accomplished by C=C double‐bond cleavage in the dihydrofuran ring and 1,6‐cyclization, which leads to 3,4‐dihydroquinolines. The latter can be easily oxidized to quinolines or reduced to tetrahydroquinolines. For dihydrofuran‐3‐carboxylates, reduction proceeds with retention of the dihydrofuran ring and affords a tricyclic dihydrofuroquinoline core under harsher conditions. The proposed general reaction pattern was supported by results of DFT calculations. Moreover, a similar reductive system can be successfully applied in the conversion of dihydrofuran acyclic precursors, γ‐(o‐nitroaryl) α,β‐unsaturated carbonyl compounds, into quinoline derivatives.

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The concept of a system develops together with all system analysis. But the starting point of defining a system is to compare it with the environment, the outer shell. The environment is a very important concept, covering what is not included in the system, and the system is a finite set of objects isolated from the environment. There are many different connections that form the relationship between the environment and the system. Separating the system from the environment is the primary task of system analysis. The vital activity of the system and the result of solving the problem depend on it. But the fundamental aspect of consistency is very important, which is that the system as a whole does not have the properties of its elements. The main feature of the tasks of system analysis is the optimality of the decisions taken, that is, not just the solution of the problem, but the development of such recommendations that would guarantee the optimality of its solution most fully and in the shortest possible time.

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