Synthesis and reactivity of some 8-substituted tricyclo[3.2.1.02,4]octane derivatives

Cyclopropyl formation by addition of methylene units (derived from the cuprous chloride catalyzed decomposition of diazomethane) to 7-norbornadienyl acetate occurs with predominate exo addition to the double bond nearer the acetate function. The products are exo- and endo-syn-tricyclo[3.2.1.02,4]octen-6-yl 8-acetates (VII and VIII) in the ratio 5 to 1. Reduction of these monoadducts gave exo and endo-syn-tricyclo[3.2.1.02,4]octan-8-ols (XIII and XIV). The CuCl-CH2N2 reaction with 7,7-dimethoxynorbornene gave exclusively the exo isomer (XV), which was converted by hydrolysis and reduction to the exo-syn alcohol XIII. The p-bromobenzenesulfonate ester of exo-anti-tricyclo[3.2.1.02,4]octan-8-ol underwent acetolysis at 206° with a rate constant of 8·0 × 10−5 sec−1, indicating that the exo-cyclopropyl group has little effect on solvolytic activity in this ring system.