2-Oxo-7-norbornyl cations and l-eyano-7-norbornyl cations have been generated from various precursors, mostly derivatives of bicyclo[3.2.0]hep- tane. Whereas 2-bromobicyclo[3.2.0]heptan-3-one (17) solvolyzed exclusively with formation of 2-methoxybicyclo[3.2.0]heptan-3-ones (19,20), the analogous diazonium ion rearranged in part to give syn-7-methoxynorbornan-2-one (29). The epimeric 2-brosyloxybicyclo[3.2.0]heptane-2-carbonitriles (34,35) solvolyzed with predominant migration of C-7, yielding l-cyano-7-norbomyl derivatives without significant anti -*syn leakage. Similarly, the decomposition of 5-cyanobicyclo[3.2.0]heptane-2-diazonium ions (47) led to 7-hydroxynor- bornane-l-carbonitrile (38) in a stereospecific manner. Slightly lower stereoselectivity (ca 90%) was observed in solvolyses of labeled l-cyano-7-norbornyl triflate (39). While the stereochemical data conform with those of the parent system, the lack of bridge flipping (40242) points to graded destabilization of bridged and open ions
