FIELD: organic chemistry, antibiotics, chemical technology. SUBSTANCE: invention relates to 12,13-dihydroxy-derivatives of tylosin of the general formula (I) 
wherein R is oxygen atom; R1 means CHO, CH=NOH, CH(OCH3)2; R2 is hydrogen atom, micarosyl of the formula 
; R3 means N(CH3)2,NO(CH3)2, 
means double or simple bond, to new semi-synthetic compounds of macrolide class and to method for their preparing. Method involves oxidation of 13-hydroxy-derivative to 12,13-dihydroxy- compound that can be subjected further to some reactions, such as oximination, reduction (catalytic, electro- chemical) or hydrolysis yielding corresponding dihydro- or tetrahydro-12,13-dihydroxy-derivatives. EFFECT: improved preparing method. 18 cl, 10 ex
