Cycloaddition of dihaloketenes with trimethylsiloxycycloolefins and fluorination of the products

Abstract The generation of difluoro-, dichloro-, and dibromoketene by the activated zinc dehalogenation of the corresponding acetyl chlorides in the presence of trimethylsiloxycycloolefins were found to yield (2+2) cycloaddition products in good yield. Subsequently, the trimethylsiloxy groups of the products were replaced by fluorine with phenyltetrafluorophosphorane, a selective fluorinating agent.