‘Inside-out’ chirality discovered by chance could have been missed in many molecules

Chemists have discovered the first small molecule with a type of isomerism thought to only exist in macromolecules like rotaxanes.¹ The finding came about by chance when the researchers realised that the characterisation data of a natural product they had synthesised didn’t match the real thing: they had made the wrong, inside-out isomer. The team behind the work thinks there could be many more cases like this that have gone undiscovered.