Search results
Results From The WOW.Com Content Network
The process, which is catalyzed by platinum supported by aluminium oxide, is exemplified in the conversion methylcyclohexane (a naphthene) into toluene (an aromatic). [2] Dehydrocyclization converts paraffins (acyclic hydrocarbons) into aromatics. [3] A related aromatization process includes dehydroisomerization of methylcyclopentane to benzene:
Cyclopentadiene is a highly reactive diene in the Diels–Alder reaction because minimal distortion of the diene is required to achieve the envelope geometry of the transition state compared to other dienes. [11] Famously, cyclopentadiene dimerizes. The conversion occurs in hours at room temperature, but the monomer can be stored for days at ...
There is a notable rate enhancement when certain Diels–Alder reactions are carried out in polar organic solvents such as dimethylformamide and ethylene glycol, [13] and even in water. [14] The reaction of cyclopentadiene and butenone for example is 700 times faster in water relative to 2,2,4-trimethylpentane as solvent. [14]
CH 3 CH 3 → 2 CH 3 ⋅. Because C−C bond energy is so high (377 kJ/mol), [18] this reaction is not observed under laboratory conditions. More common examples of cracking reactions involve retro-Diels–Alder reactions. Illustrative is the thermal cracking of dicyclopentadiene to produce cyclopentadiene.
In organic chemistry, pentadiene is any hydrocarbon with an open chain of five carbons, connected by two single bonds and two double bonds. All those compounds have the same molecular formula C 5 H 8. The inventory of pentadienes include: 1,2-pentadiene, or ethyl allene, H 2 C=C=CH−CH 2 −CH 3. [1]
Water can be broken down into its constituent hydrogen and oxygen by metabolic or abiotic processes, and later recombined to become water again. While the water cycle is itself a biogeochemical cycle, flow of water over and beneath the Earth is a key component of the cycling of other biogeochemicals. [8]
Cp 2 Fe 2 (CO) 4 was first prepared in 1955 at Harvard by Geoffrey Wilkinson using the same method employed today: the reaction of iron pentacarbonyl and dicyclopentadiene. [7] [8] 2 Fe(CO) 5 + C 10 H 12 → (η 5-C 5 H 5) 2 Fe 2 (CO) 4 + 6 CO + H 2. In this preparation, dicyclopentadiene cracks to give cyclopentadiene, which reacts with Fe(CO ...
The Buchner ring expansion reaction was first used in 1885 by Eduard Buchner and Theodor Curtius [1] [2] who prepared a carbene from ethyl diazoacetate for addition to benzene using both thermal and photochemical pathways in the synthesis of cycloheptatriene derivatives. The resulting product was a mixture of four isomeric carboxylic acids ...