1,3-Dipolar cycloaddition reaction of acetonitrile oxide to cis- and trans-22-hydroxy-24-alkoxycarbonyl-Δ(23)-steroids is investigated. An unusual stereochemical course of the cycloaddition, leading to the same set of the isoxazoline adducts for both (Z)- and (E)-disubstituted olefins is revealed. It is shown, the reaction is regioselective and all possible 4',5'-diastereoisomers of resulting isoxazolines