Abstract A practical synthesis of 7-methylenebicyclo [3.3. 1] nonan-3-one 2 by the fragmentation of 1, 3-adamantanediol 8, which was prepared effectively by the ruthenium- catalized oxyfunctionalization of 1-adamantanol 7, is described. Characteristic transannular cyclization of 2 leading to a novel tricyclic system, 1-hydroxy-4-protoadamantanone 9, via the corresponding exo-epoxide 10 is also presented.
![7-Methylenebicyclo[3.3.1]nonan-3-one Structure](https://image.chemsrc.com/caspic/376/17933-29-8.png)
![spiro[bicyclo[3.3.1]nonane-3,2'-oxirane]-7-one Structure](https://image.chemsrc.com/caspic/199/29681-64-9.png)
