Photolysis of some 1-substituted cycloocta-1,5-dienes: synthesis of 1-fluorotricyclo[3,3,0,02,6]octane

A study of the photolytic behaviour of several derivatives of cycloocta-1,5-diene as possible precursors of bridgehead-substituted tricyclo[3,3,0,02,6]octanes is described. Of the substrates examined, only 1-fluorocycloocta-1,5-diene successfully underwent photocyclization giving 1-fluoro-tricyclo[3,3,0,02,6]octane. 1- Bromocycloocta-1,5-diene suffered fission of the carbon-bromine bond, while cycloocta-1,5-diene-1-carbonitrile afforded a mixture of at least four unsaturated isomers.