Polyhalogenated 2‐Azabicyclo[2.2.1]heptanes from Polyhaloaldimines and Cyclopentadiene via Cycloaddition and Wagner‐Meerwein Rearrangement

2‐Arylsulfonyl‐2‐azabicyclo[2.2.1]hept‐5‐enes, synthesized via the cycloaddition of chloral‐ or dichloro(phenyl)acetaldehyde N‐arylsulfonylimines to cyclopentadiene, undergo Wagner‐Meerwein rearrangement under the action of bromine or chlorine to afford 3‐polychloro‐6,7‐dyhalogenated 2‐arylsulfonylazabicyclo[2.2.1]heptanes.