 In step 1 the alkyl halide 1-iodo-3-butene 1 is converted to a cyanozinc cuprate 2 (by transmetalation of the organozinc iodide with copper cyanide) which reacts in the next step with 1-nitrocyclopentene 3 in a nucleophilic addition whereby the nitronate 4 is captured by phenylselenenyl bromide to the selenium intermediate 5.Hydrogen peroxide oxidation of 5 yields the nitroalkene 6 as a mixture of "syn" and "anti" isomers.A [4+2]cycloaddition with "n"-butylenol ether in presence of trimethylaluminium gives the nitronate 7 and a second [3+2]cycloaddition by heating in presence of potassium carbonate gives the nitroso acetal 8.