Compounds that contain more than two double bonds are called polyenes

the regiospecific synthesis of 1,5- disubstituted-cyclooctatetraene derivatives.

Polyenes and dienes share many of their properties

Richard Willstätter's original synthesis (4 consecutive on acycloctane framework) gives relatively low yields. Reppe'ssynthesis of cyclooctatetraene, which involves treating at high pressurewith a warm mixture of nickel cyanide and , was much better, with near90%

Azulene is an organic compound and an isomer of naphthalene

The π bonds in COT react as usual for olefins, rather than asaromatic ring systems. Mono- and poly can be generated by reaction of COTwith orwith . Various otheraddition reactions are also known. Furthermore, canbeen synthesized via the of cyclooctatetraene. COTitself —and also analogs with side-chains— have been used as metalligands and in .

Willstätter noted that the compound did not exhibit the expectedaromaticity. Between 1939 and 1943, chemists throughout the USunsuccessfully attempted to synthesize COT. They rationalized theirlack of success with the conclusion that Willstätter had notactually synthesized the compound but instead its isomer, . Willstätter respondedto these reviews in his autobiography, where he noted that theAmerican chemists were 'untroubled' by the reduction of hiscyclooctatetraene to cyclooctane (a reaction impossible forstyrene). In 1947, at Ludwigshafen at lastrepeated Willstätter's synthesis.