(Figure presented.) The aim of this work was to synthesize and study the antituberculosis activity of spirocyclic inhibitors of the MmpL3 protein of M. tu- berculosis containing the 1-oxa-9-azaspiro[5.5]undecane scaffold. Optimization of the initial structure was performed with consideration of the results of molecular docking. The resulting compounds, characterized by the chemical diversity of the peripheral fragment, showed high activity against the antibiotic-sensitive strain H37Rv and some multiresistant strains of M. tuberculosis, exceeding the activity of the comparator drug.