Vinylcyclopropane of general formulae I in which X, Y in each case are O or NH, wherein X and Y cannot have the same meaning, R1 is a linear or branched C1-C8-alkyl radical, which can be interrupted by O, S, an ester group or a urethane group, R2 is a linear or branched C2-C10-alkylene radical, which can be interrupted by O, S, an ester group or a urethane group, R3 is a hydrocarbon radical with 1 to 20 carbon atoms, which additionally can contain one or more N, O or S atoms, and n is 1, 2, 3 or 4, preferably 1 or 2. The vinylcyclopropanes are characterized by a low shrinkage and a high reactivity on radical polymerization and are suitable in particular for the preparation of dental materials.