Logic of human-system-interaction in planning complex strategies for chemical syntheses

New HSI-logic in planning complex chemical syntheses are illustrated by application of Corey´s or Ugi-Dugundji approaches to design of new pharmaceuticals. The second. approach (known worldwide as the D-U model) allows to generate synthetic pathways to required compounds, neglecting very expensive process of searching through enormously large databases on chemical reactions. The main features of both approaches are briefly discussed, and finally our own extension of the D-U model based on the application of various methods of machine learning is briefly discussed.