Tetravinylallene is new improbable molecule out of the laboratory of M.S. Sherburn (Elgindy et al. DOI). This blog has been reporting about earlier stranger things such as divinylallene in 2011 and 3-vinyl-1,4,heptadiene in 2012. They all belong to a class of hydrocarbons called dendralenes that have some relevance as simple building blocks for complex molecules. The last step in the tetravinylallene synthesis was a Negishi coupling followed by an in-situ carbon framework rearrangement described in the article rather vaguely as a 1,5-transposition. Unsurprisingly the compound in neat form is unstable and quickly lapses into a polymeric state. A benzene solution is workable. A reaction with N-phenylmaleimide results in a succession of three Diels-Alder reactions and an electrocyclization and a heptacycle as major product.