FIELD: chemical industry. SUBSTANCE: method of preparing oxazolidinecarboxylic acid of formula I; 
wherein R′ is hydrogen, alkyl, or alkali or alkaline-earth metal atom; R1 is benzoyl or radical R2-O-CO-;; R2 is C1-8 alkyl; R3 and R4 are hydrogen, alkyl, phenyl optionally substituted by methoxy radical, or R3 is C1-4 alkoxy, and R4 is hydrogen. Ester of compound of formula II: 
wherein R′ is C1-4 alkyl and R1, R3, R4 are as defined above, is selectively iodinated, and the resulting product is subsequently saponified. Compound of formula I is useful for preparing therapeutically active taxoids of formula III: 
. EFFECT: more efficient preparation method.
