First Synthesis of the Dendralene Family of Fundamental Hydrocarbons

A neglected group of highly unsaturated hydrocarbons was how the dendralenes were described 16 years ago in a review in Angewandte Chemie. These compounds are neglected no more! The hitherto unknown [5]-, [6]- (see scheme), and [8]dendralenes are synthesized by thermolysis of masked sulfolene derivatives which, in turn, are prepared by Stille coupling. The same approach offers an improved route to pure samples of [3]- and [4]dendralene, the full spectroscopic details of which are reported for the first time.