The reaction of tetracyanoethylene with alpha,beta-unsaturated aldehydes under hydrochloric acid catalysis leads to 2,4-dialkyl-7-imino-6-oxabicyclo[3.2. 1]oct-3-ene-1,8,8-tricarbonitriles. The structures of these new cyclohexene derivatives were determined by NMR experiments and X-ray crystallography. (c) 2007 Elsevier Ltd. All rights reserved.