The condensation reaction of chloromethylbenzyl ether with chloro(bromo)-substituted benzaldehydes in the presence of sodium hydroxide under the conditions of interphase catalysis (catalyst – TEBAC) has been studied. The synthesis method for 2-benzyloxy-3-aryloxiranes has been developed. The synthesis of oxiranes takes place stereoselectively with the formation of trans-isomers. The obtained compounds have been studied as antimicrobial additives for lubricating oils and fuels. Keywords: chloro(bromo)-substituted benzaldehydes; chloromethylbenzyl ether; trans-isomers; 2,3-disubstituted oxiranes; inretphase catalysis; antimicrobial additives.