One Hand Only: Chiral Fragmentation Control to Remove the Unwanted Mirror-Image Molecule in the Soai Reaction

Many molecules exist in two mirror-image forms, like left and right hands. Living thingsusually need only one of them. The 2026 Nobel Prize in Chemistry recognised two ideas thatexplain how one mirror-image form can take over a reaction: the nonlinear effect (Kagan) andautocatalysis (Soai). This note proposes a new area, Geometric Chemistry, which describessuch reactions with simple “maps” of conditions, much like a phase diagram. Our firstquestion is practical: how can we reduce the unwanted mirror-image molecule (R)to nearly zero? We treat it as an optimisation problem: choose the reaction conditionsthat minimise R subject to the limits of time, material and noise.