Nitrogen Inversion as a Diastereomeric Relay in Azasugar Synthesis: The First Synthesis of Adenophorine

A temperature-dependent relay of chirality is based on the inversion of the nitrogen lone pair in cyclic azasugars. Elimination from the conformation preferred at a given temperature leads to a cyclic imine, and in a subsequent nucleophilic attack the stereochemical information is relayed.