Addition of ICl to Norbornene. The Preparation and Photochemical Isomerization of syn-7-Iodonorbornene

The addition of ICl to norbornene in the presence of pyridine yields nortricyclyl iodide (1c), endo-2-chloro-exo-3-iodonorbornane (2c), and syn-7-iodo-exo-2-chloronorbornane (3b) as the major products. Base-catalyzed elimination of HCl from 3b yields syn-7-iodonorbornene (6a) which is isomerized photochemically to anti-7-iodonorbornene (6b).