On the mechanism of the rearrangement of N‐aryl α,α‐dichloroketimines with lithium aluminium hydride

Experimental evidence is provided that the rearrangement of N‐aryl α,α‐dichloroketimines with lithium aluminium hydride in ether, observed as a competitive reaction during the stereospecific synthesis of cis‐aziridines, proceeds via consecutive transformation of α‐chloroaziridines into azirinium chlorides and α‐imidoylcarbenium ions, the latter being trapped by chloride anion to afford β‐chloroenamines, which furnish rearranged anilines on treatment with lithium aluminium hydride.