Endo Tetrahydrodicyclopentadiene

Dicyclopentadiene, conversion to endo-tetrahydrodicyclopentadiene and to adamantane, 43, 8 a,a-Dichlorotoluene, conversion to ,a-difluorotoluene, 44, 40... 

Preparation B. Ault and Kopet2 describe as an introductory organic experiment a procedure for the preparation of adamantane by isomerization of endo-tetrahydrodicyclopentadiene by the method of Schleyer but the product is isolated from a hexane extract of the reaction mixture as the beautifully crystalline inclusion complex with thiourea.3 As noted in 1, 1164, the ratio in this complex is 3.4 molecules of host per molecule of guest hydrocarbon. Although the reaction time is only 1 hour, the yield (15%) is about the same as that reported for a reaction time of 8-12 hours. 

As can be seen, the relative volatility of both propylbenzene and 4-methylethylbenzene were more than 1.500, and the relative volatility of endo-Tetrahydrodicyclopentadiene was less than 0.600. The further away from 1 the relative volatility of them is, the more easily they can be separated from indane. Thus, the separation of the remaining components become complicated. 

There are a lot of indane, 1,2,4-Trimethylbenzene, endo-Tetrahydrodicyclopentadiene in the hydrogenated C9 arenes, which were valuable resources for the development of fine chemicals. The article preliminary selected three kinds of representative solvents sulfolane, glycerol and dioctyl phthalate. First of all, the VLB date were obtained by the single stage gas-liquid equilibrium still as well as the Aspen Plus, and the relative errors between experiment and correlative simulation were much less than 5%, which proved the vapor-liquid equilibrium experiments were accurate and reliable. 

Isomerization and oligomerization of olefins are important reactions in chemical industry and they have been studied extensively in acidic IL systems. For purpose of easy catalyst separation and recovery, the supported chloroaluminate IL-phase catalyst was applied in endo-tetrahydrodicyclopentadiene isomerization. Scheme 2.26 [108]. As a typical operation, sodium montmorillonite (Na-MMT) was first transformed to l-hexadecyl-3-methyl-imidazolium (HDMI) montmorillonite (I-MMT) through ion exchange with [HDMIjCl and used as the support. Subsequently, chloroaluminate IL [HDMIjCl was supported onto the I-MMT by impregnation ([HDMIjCl-AlClj/I-MMT). Under optimized reaction conditions, >99% yield to exo-tetrahydrodicyclopentadiene was obtained over [HDMIjCl-AlClj/I-MMT catalyst at 50 °C in 2 h. The conversion of endo-tetrahydrodicyclopentadiene was 82.7% when Na-MMT was used as the support directly without IL modification. 

Fluonnation over cobalt trifluonde over a temperature gradient of 200 to 250 °C converts ern-dicyclopentadiene to a mixture of endo- and exo-perlluoro-tetrahydrodicyclopentadiene and perfluorobicyclo[5.3 Ojdecane [21] (equation 14). 

The Lewis-acid-catalysed rearrangement of polycyclic hydrocarbons C H2 4 c (x = 1,2,3,...) into their thermodynamically more stable diamond-like isomers is usually referred to as the adamantane rearrangement . The archetype of this unique isomerization is the AlCl3-catalyzed transformation of en /o-tricyclo[5.2.1.0 ]decane (11) (tetrahydrodicyclopentadiene) into adamantane (Ad-H) (Scheme 4), which was first discovered by Schleyer " more than 30 years ago. This process is thermodynamically controlled and it involves carbenium ion intermediates which rearrange via successive 1,2-C bond and 1,3 hydride shifts. Numerous theoretical and experimental investigations have established the most direct thermodynamically feasible pathway (exo-11 -> 12 13 -> 14 -> 15 Ad-H) for the isomerization of endo-11 to adamantane. 

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