In the course of this work, different strategies have been invoked to transannularly functionalize eight- and ten-membered carbon rings. For this purpose, both intramolecular and intermolecular reactions were investigated. Two isomeric bicycles were synthesized from cyclodec-5-enol by intramolecular opening of the corresponding oxirane and iodonium ion, respectively. The relative configuration of the [5.3.1]undecan-1-ol was confirmed by a crystal structure. However, no effective influence of the hydroxyl group on the stereoselectivity of the first epoxidation or iodination of the C-C double bond or on the course of a Simmons-Smith cyclopropanation was detected. An intramolecular Crandall-Lin cyclopropanation was successfully transferred to a medium-sized ring for the first time. A tricyclic alcohol was obtained from a cyclooctene derivative. No such transannular cyclopropanation was observed on the larger cyclodecene derivative. However, transannular reactions have the potential to facilitate the synthesis of medium-sized rings in natural products.
