Willstätter responded to these reviews in his autobiography, where he noted that the American chemists were 'untroubled' by the reduction of his cyclooctatetraene to cyclooctane (a reaction impossible for styrene).

During World War II, Walter Reppe at BASF Ludwigshafen developed a simple, one-step synthesis of cyclooctatetraene from acetylene, providing material identical to that prepared by Willstätter.

They obtained the same cyclooctatetraene,[5] and they subsequently reported modern spectral characterization of many of the intermediate products, again confirming the accuracy of Willstätter's original work.

[8] However, X-ray diffraction data from H. S. Kaufman demonstrated cyclooctatetraene to adopt several conformations and to contain two distinct C–C bond distances.

[9] This result indicated that COT is an annulene with fixed alternating single and double C-C bonds.

[12] Richard Willstätter's original synthesis (4 consecutive elimination reactions on a cyclooctane framework) gives relatively low yields.

Reppe's synthesis of cyclooctatetraene, which involves treating acetylene at high pressure with a warm mixture of nickel cyanide and calcium carbide, was much better, with chemical yields near 90%:[4] COT can also be prepared by photolysis of barrelene, one of its structural isomers, the reaction proceeding via another isolable isomer, semibullvalene.

[14] Because COT is unstable and easily forms explosive organic peroxides, a small amount of hydroquinone is usually added to commercially available material.

[21] Cyclooctatetraene is chlorinated to give a [4.2.0]-bicyclic compound, which reacts further with dimethyl acetylenedicarboxylate in a Diels-Alder reaction (DA).