Abstract: A process for preparing a cyclic compound comprising subjecting a starting material in the presence of a catalyst component to metathesis reaction in the presence of an ionic liquid, wherein the starting material is a &agr;,&ohgr;-diene bearing a &agr; substituent NRR1 in the &agr; position to a double bond, wherein R is hydrogen or an organic substituent, R1 is tert-butyl, P(R)2, P(R2)2, COR, SO2PhR, COOR or CONRR2, R2is alkyl or phenyl, or R and R1 together form and in which &agr;,&ohgr;-dienes optionally bear at least one further substituent R in any other position with the exception of the &agr; position, wherein R is selected from the group consisting of hydrogen, fused or unfused aryl, alkyl, CN, COOR2 or halogen, and wherein the starting material optionally contains a member selected from the group containing at least one further substituent that is inert in the metathesis reaction and a heteroatom selected from the group consisting of branched alkyl radicals, unbranched alkyl radical