Stereospecific Synthesis of α-Substituted <i>syn</i>-α,β-Diamino Acids by the Diaza-Cope Rearrangement

Diaza-Cope rearrangement is used to make a variety of α-substituted syn-α,β-diamino acids. The rearrangement takes place with complete transfer of stereochemical integrity (>97% de and >98% ee) giving only one of four possible stereoisomers as determined by X-ray crystallography, 1H NMR, and chiral HPLC. The observed stereospecificity can be explained in terms of DFT computation. This represents the first 1,4-diaza-Cope rearrangement with a ketone.