Second-Chance Rearrangement Route to Novel 5(6)-Syn,anti-difunctional 2-Azabicyclo[2.1.1]hexanes

The first syntheses of 5,6-difunctionalized-2-azabicyclo[2.1.1]hexanes containing <i>syn</i>-hydroxy and <i>syn-</i>fluoro substituents have been effected in a stereocontrolled manner. The key reactions are regioselective additions to the aziridinium ions formed from 6-<i>exo</i>-iodo(bromo)-5-<i>endo</i>-X-2-azabicyclo[2.2.0]hexanes (X = F, OH) upon silver or mercury salt enhancement of iodide nucleofugacity.