FIELD: organic chemistry, antibiotics. SUBSTANCE: invention relates to novel 9-N-ethenyl derivatives of 9-(S)- erythromycylamine of the general formula (I) 
where R1 and R2 are similar or different and mean nitrile group, carboxyl group of the formula COOR3 where R3 means C1-C4-alkyl group or keto-group of the formula COR4 where R4 means C1-C4-alkyl group, or to their pharmaceutically acceptable salts of addition of inorganic or organic acids, and to method of their synthesis also. Invention can be useful for preparing pharmaceutical preparations for control of bacterial infections. EFFECT: new compounds indicated above, valuable antibacterial properties. 18 cl, 1 tbl
