83 The reaction of olefins with polynitromethanes is a known method for the preparation of 3,3-dinitroisoxazolidines [1, 2]. Previously, we studied reactions of tetranitromethane and halotrinitromethanes with unsaturated compounds containing small rings [3–8]. It was shown that the reactions of polynitromethanes with strained alkenes and acetylenes give a range of Nand O-containing heterocycles (dinitroisoxazolidines, nitroisoxazolines, dinitropiperidones, dinitroaziridines), tetranitropropanes, and gem -dinitrocyclopropanes [3–9]. No data on reactions of oxiranes with polynitromethanes have been reported so far, although these reactions can be considered as a new method for generation of alkyl nitronates, which are precursors of diverse heterocycles, and as a possible approach to the synthesis of trinitroalkanols. The trinitromethyl anion is known to show ambident properties, functioning as either an Oor a C-nucleophile depending on the substrate nature [1, 4, 7]. We suggested two possible pathways for its reaction with epoxides (Scheme 1), namely, pathway A including C-alkylation of the oxonium cation I to give 3,3,3-trinitropropanols II (two-component reaction) and pathway B including O-alkylation of the oxonium cation I with generation of an unstable nitronic ester III, which can either decompose to α -hydroxy ketone IV or undergo [3+2]-cycloaddition in the presence of an olefin to give 3,3-dinitroisoxazolidines V (three-component reaction).