In Search of Wasserman's Catenane.

We repeat the earliest claimed [2]catenane synthesis, reported by Wasserman over 60 years ago, in order to ascertain whether or not a nontemplate, statistical synthesis by acyloin macrocyclization does indeed form mechanically interlocked rings. The lack of direct experimental evidence for Wasserman's catenane has led to it being described as a "prophetic compound", a technical term used in patents for claimed molecules that have not yet been synthesized. Contemporary synthetic methods were used to reconstruct Wasserman's deuterium-labeled macrocycle and other building blocks on the 10-100 g reaction scale necessary to generate, in principle, ∼1 mg of catenane.