3727-31-9Relevant articles and documents
Solvent-free conversion of linalool to methylcyclopentadiene dimers: A route to renewable high-density fuels
Meylemans, Heather A.,Quintana, Roxanne L.,Goldsmith, Bryan R.,Harvey, Benjamin G.
experimental part, p. 465 - 469 (2012/02/14)
Neat biofuel in HD: Linalool, a linear terpene alcohol, can be selectively converted by ruthenium metathesis catalysts under solvent-free conditions to 1-methyl-cyclopent-2-enol and isobutylene in quantitative yield. Dehydration of the alcohol under mild conditions followed by low-temperature thermal dimerization yields methylcyclopentadiene dimer, which can be readily converted into a high-density fuel.
Pyrolysis and oxidation of anisole near 1000 K
Pecullan,Brezinsky,Glassman
, p. 3305 - 3316 (2007/10/03)
Experiments near 1000 K have revealed the thermal decomposition of anisole to proceed exclusively via homolysis of the O-CH3 bond. The anisole decay was observed to be first order even in the presence of oxygen. The distribution of reaction intermediates was virtually independent of equivalence ratio, φ ≡ ([anisole]/[O2])/([anisole]/[O2]) stoichiometric. Phenol, cresols, methylcyclopentadiene, and CO were major products. Minor species included benzene, cyclopentadiene, ethane, and methane. Trace yields of ethene, toluene, and naphthalenes were observed under all conditions; trace C2-C4 species including acetylene, allene, and 1,3-butadiene were observed only in the oxidation experiments. Oxidation occurs preferentially through methylcyclopentadiene. A multichannel reaction scheme is proposed involving the formation of a chemically activated adduct from phenoxy and methyl. The complex reacts to form primarily cresols and methylcyclopentadiene + CO either directly or subsequent to stabilization. A kinetic model for anisole pyrolysis has been developed to predict the disappearance of anisole and the production of reaction intermediates. Excellent agreement is obtained between experimental data and model predictions of anisole, CO, methylcyclopentadiene, and total phenolics.
Zur Aromatisierung von n-Heptan an Pt-Sn/Al2O3- und Pt-Ir/Al2O3-Katalysatoren
Wilde, M.,Feldhaus, R.,Anders, K.,Neubauer, H.-D.
, p. 919 - 925 (2007/10/02)
The aromatization of n-heptane and methylcyclopentane has been investigated under normal pressure over catalysis with very different metal and acid functions.Under these conditions, Pt-Sn/Al2O3 is characterized by high activity and outstanding selectivities for dehydrogenation and dehydrocyclization via 1,6 ring closure.
On the Thermal Isomerization and Aromatization of Hex-1-ene-5-yne
Remmler, M.,Ondruschka, B.,Vorwerk, D.,Olk, B.,Pola, J.,Kubat, P.
, p. 699 - 709 (2007/10/02)
The gas phase conversion of hex-1-ene-5-yne induced by conventional hot-wall pyrolysis, very low pressure pyrolysis (VLPP-MS technique) and continuous-wave CO2 laser-photosensitized (SF6) pyrolysis was studied at 350-1100 deg C.The pyrolysis experiments were performed in quartz reactors and the reaction products analyzed by capillary gas chromatography, mass and n.m.r. spectroscopy.The pattern of conversion suggested for all the processes involved a sequence of isomerizations ( -> hexa-1,2,5-triene -> methylcyclopentenes), aromatization (into benzene via pentafulvene) and C-C bond rupture (into propargyl and allyl radicals).The formation of benzene is explained by reaction network with methylenecyclopentenes and methylcyclopentadienes as key intermediates.
66. The Hydrolysis of Ethyl 1-Methyl-2,4-cyclopentadiene-1-carboxylate by Nonenzymatic and Enzymatic Methods. Carbon-Carbon vs. Carbon-Oxygen Bond Cleavage
Burger, Ulrich,Erne-Zellweger, Dominique,Mayerl, Christa
, p. 587 - 592 (2007/10/02)
The title ester 5 is shown to undergo C-C bond cleavage under the conditions of basic ester hydrolysis (KOH/EtOH) with formation of potassium ethyl carbonate (6) and the tautomeric methylcyclopentadienes 7 and 8.In contrast, porcine liver esterase (PLE, EC 3.1.1.1) cleanly hydrolyses 5 to give the isolable 1-methyl-2,4-cyclopentadiene-1-carboxylic acid (13).The latter undergoes thermal dimerization with conservation of the geminal-substitution pattern.The configuration of the Diels-Alder adduct 17 is ascertained by it photochemical transformation into bishomocubane dicarboxylic acid 12, easily distinguished by its C2 symmetry.Under the conditions of acid-catalyzed hydrolysis, dimerization of ester 5 and polymerization prevail, unless low acidic concentration is used.The dimer 9 of 5 has one ester function that is reluctant to undergo basic hydrolysis.
Carbene Reactions, XVIII. Thermal Behaviour of 7-Alkylidenebicycloheptadiene Derivatives
Hoffmann, Reinhard W.,Riemann, Achim,Mayer, Bernhard
, p. 2493 - 2513 (2007/10/02)
Thermolysis of 7-alkylidenenorbornadienes 2 results in a retro-Diels-Alder cleavage to fulvenes and acetylene.A different mode of cleavage - into benzene and a carbene - is observed with such derivatives of 2 which carry ?- or ?-donor functions at C-8.The dependence of the reaction pathways on the nature of the substituent at C-8 is discussed on the basis of MO-calculations.
THE DIAZO ROUTE TO 2-VINYLCYCLOPROPYLIDENES
Krimse, Wolfgang,Chiem, Pham Van,Henning, Paul-Georg
, p. 1441 - 1452 (2007/10/02)
2-Vinylcyclopropylidene (2), 3-methyl-2-vinylcyclopropylidenes (79,80) and 2-(1-propenyl)cyclopropylidenes (95,97) were generated from the corresponding nitrosoureas in methanol at room temperature.The diazo route is initiated by the formation of 2-vinylcyclopropanediazonium ions (e.g. 43) which do not undergo 1,3-carbon shifts.No cyclopentenyl products were found in weakly basic methanol where the diazonium ions prevail.Ring opening of the diazonium ions gives pentadienyl cations and products derived therefrom.Delocalisation of the pentadienyl cations was demonstrated by the distribution of deuterium and methyl labels.In the presence of strong base, 1-diazo-2-vinylcyclopropanes (e.g. 48) arise by deprotonation of the diazonium ions.Rearrangement of 48 was excluded by independent generation of the potential product, 4-diazocyclopentene (103).Substantial quantities of 3-methoxycyclopentene (108) were obtained from 103, but not from 48.The 2-vinylcyclopropylidenes 2, 79 and 95, arising by loss of nitrogen from the corresponding diazo compounds, undergo allene formation and Skatteboel rearrangement competitively.Cis-oriented methyl groups at either C-2 (81) or C-2' (97) prevent the Skattebol rearrangement.The cyclopentenylidenes 3 and 83 yield 4-methoxycyclopentes (52,86) in excess over cyclopentadiens (4,84).In the presence of methyl vinyl ether, cycloaddition of 3 and electrophilic addition of 3-cyclopentenyl cation (51) occured in a 1:14 ratio.Stereospecific formation of 52 indicates protonation of a 'foiled carbene' (3a) to give a bishomocyclopropenyl ion (51a).Our studies confirm that the various routes to 2-vinylcyclopropylidenes converge at the carbene stage.
Chemistry of gem-Dihalocyclopropanes. XX. The Effect of Methyl and Phenyl Substituents on the Vinylcyclopropylidene-Cyclopentenylidene Rearrangement
Holm, Kjetil H.,Skatteboel, Lars
, p. 783 - 794 (2007/10/02)
Reactions of gem-dibromocyclopropanes of the general structure 1 with methyllithium have been studied.In the most cases cyclopentadienes and/or vinylallenes are the products formed.The results obtained give evidence of a profound substituent effect on the carbene-carbene rearrangement leading to cyclopentadienes.We believe the effect is essentially steric in origin.The results support the mechanism proposed for the rearrangement.
