PURPOSE: To obtain the titled compound useful as a synthetic raw material or intermediate for physiologically active substances in high yield in short steps, by nitrating a cycloalkene with nitrogen tetroxide and/or nitrogen dioxide in the presence of a catalyst consisting of a metal of Group VIII.

CONSTITUTION: A cycloalkene of formulaI(n is an integer 3W18) is nitrated with nitrogen tetroxide and/or nitrogen dioxide in the presence of a catalyst consisting of a metal of Group VIII, e.g. palladium acetate or nickel chloride, to give a 1-nitrocycloalkene of formula II. The nitration reaction is preferably carried out generally in a solution system prepared by dissolving the raw material cycloalkene in a solvent, e.g. acetic acid or chloroform, at ordinary pressure and 5W80°C. The resultant 1-nitrocycloalkene of formula II can be converted into the corresponding oxime by the hydrogenation, and the oxime is then converted into a lactam useful as a raw material for polyamides, e.g. nylon, by the Beckmann rearrangement.