Adamantane (ADM) was synthesized by isomerization of exo-tetrahydrodicyclopentadiene (exo-THDCPD) using chloroaluminate ionic liquids (ILs) as the catalyst. The yield of ADM was optimized to obtain 21.9% under the conditions of 70 °C for 6 h and pyridine hydrochloride/aluminum trichloride catalyst (PHC/AlCl3) at an AlCl3mole fraction of 0.65. Under these conditions, the selectivity of ADM was 66% and the product mixture was easily recovered from the IL catalyst phase. It is proposed that endo-/exo-isomerization occurs via a carbocation mechanism leading to ADM, the main product, with ring-opening to decalin and other C10H18by-products. © 2009 Elsevier B.V. All rights reserved.
Huang, M. Y., Wu, J. C., Shieu, F. S., & Lin, J. J. (2009). Isomerization of exo-tetrahydrodicyclopentadiene to adamantane using an acidity-adjustable chloroaluminate ionic liquid. Catalysis Communications, 10(13), 1747–1751. https://doi.org/10.1016/j.catcom.2009.05.030