Abstract: A method for the synthesis of a molecular lasso structure in which a linear moiety is covalently attached to a cyclic moiety and with its free end is partially threaded through the orifice formed by the cyclic moiety, including the following steps: 1) provision of a cyclic and a first linear structural element and establishing conditions in which the first linear structural element is threaded through the orifice of the cyclic moiety; 2) covalently attaching a stopper element to one terminal end of the linear structural element; 3) separating unthreaded from threaded molecular assemblies by chemical or physical separation; and 4) reacting the threaded molecular assemblies with a second linear structural element so that it is covalently attached to the first linear structural element at its end opposite to the end where the stopper is attached, and so that the second linear structural element is covalently attached to the cyclic moiety.