The [1+2] cycloaddition of ethyl nitrodiazoacetate to various methylenecyclopropanes afforded 1-ethoxycarbonyl-1-nitropolyspirocyclopropanes. These compounds were used in the synthesis of first representatives of nitrosubstituted triangulanes. Nitrospiropentane was prepared also by dehydrohalogenation of 1-bromomethyl-1-(nitromethyl)cyclopropane.