Reagents which add to the norbornene double bond under a variety of conditions without undergoing skeletal rearrangement do so to afford the exo-cis product (see for example, oxymercuration, lo hydroboration, l'de~ teration,'~!'~ hydrocarb~ xylation,~~ nitr~ sylation,'~ and diimidizationI6). The preference for exo-cis elimination in exo-2-substituted norbornanes has been demonstrated" from the fact that 2-chloro-and 2-bromonorbornene ...
