Cyclopentane Ethylene

The following acid-catalyzed cyclizations leading to steroid hormone precursors exemplify some important facts an acetylenic bond is less nucleophilic than an olelinic bond acetylenic bonds tend to form cyclopentane rather than cyclohexane derivatives, if there is a choice in proton-catalyzed olefin cyclizations the thermodynamically most stable Irons connection of cyclohexane rings is obtained selectively electroneutral nucleophilic agents such as ethylene carbonate can be used to terminate the cationic cyclization process forming stable enol derivatives which can be hydrolyzed to carbonyl compounds without this nucleophile and with trifluoroacetic acid the corresponding enol ester may be obtained (M.B. Gravestock, 1978, A,B P.E. Peterson, 1969). 

Hydrocarbons, compounds of carbon and hydrogen, are stmcturally classified as aromatic and aliphatic the latter includes alkanes (paraffins), alkenes (olefins), alkynes (acetylenes), and cycloparaffins. An example of a low molecular weight paraffin is methane [74-82-8], of an olefin, ethylene [74-85-1], of a cycloparaffin, cyclopentane [287-92-3], and of an aromatic, benzene [71-43-2]. Cmde petroleum oils [8002-05-9], which span a range of molecular weights of these compounds, excluding the very reactive olefins, have been classified according to their content as paraffinic, cycloparaffinic (naphthenic), or aromatic. The hydrocarbon class of terpenes is not discussed here. Terpenes, such as turpentine [8006-64-2] are found widely distributed in plants, and consist of repeating isoprene [78-79-5] units (see Isoprene Terpenoids). 

Investigation of Ethane, Propane, Isobutane, Neopentane, Cyclopropane, Cyclopentane, Cyclohexane, Allene, Ethylene, Isobutene, Tetramethylethylene, Mesitylene, and Hexamethylbenzene. Revised Values of Covalent Radii (by Linus Pauling and L. O. Brockway)... 

In the case of the cyclopentane oxirane 424, fluorination [KHFj, Me0(CH2)20H] proceeded to give preferably one fluoroalcohol, 426 (61%) over the isomeric one, 425 (7%), possibly by the influence of the benzyloxy-methyl group. Similarly (KHF2, ethylene glycol, 160°), another oxirane, 427, was converted into 428 (30%). 2-C-(Fluoromethyl)-/ T6>-inositol (429)... 

Biradical I would yield cyclopentene plus ethylene, biradical II the hepta-1,6-diene. Process I may have a lower energy of activation because of the stabilization of the free electron by the secondary carbon atom and also because less energy is required to compress the appropriate carbon-carbon bond, in the cyclopentane ring to yield the cyclopentene, than to rupture the ring to give the diene. 

Cyclohexanol, Cyclopentane, Cyclopentene, 1,2-Dichloroethane, Diethyl phthalate, 1,4-Dioxane, Ethephon. Ethylamine, Ethylene dibromide, Ethylenimine, p-Propiolactone, Tetraethyl pyrophosphate, TCDD, 1,1,1-Trichloroethane, Trichloroethylene, Vinyl chloride Ethylene chlorohydrin, see Bis(2-chloroethyl) ether Ethylenediamine, see Ethylene thiourea. Maneb Ethylene glycol, see Bis(2-chloroethyl) ether, 1,2-Dichloroethane, Ethylene chlorohydrin. Ethylene dibromide... 

Comparable results are known for the decomposition of nickela-cyclopentane complexes wMch lead, depending on the ligand-to-metal ratio to cyclobutane, 1-butene and ethylene... 

In the case of co-polymers with cyclic olefins other than NB, Naga et al. performed the co-polymerizations of ethylene or propylene with cyclopentene by using a number of bridged metallocene catalysts, and then investigated the peak melting temperatures and crystalline structures of the resultant co-polymers, all containing cyclopentane units. In 2004, Waymouth and Lavoie reported on the catalytic properties of a series of... 

Recent advances in Cp-based catalyst technology made it possible to produce unique microstructure polymers from ethylene and BD. Longo and co-workers have reported in a series of publications the unprecedented cyclo-co-polymerization of ethylene and BD using a sterically encumbered isospecific metallocene F13-8 with MAO, which affords 1,2-cyclopropane rings together with 1,2-cyclopentane rings in the polymer chain, both with high trans-... 

Cycloalkanes may be pyrolized in a manner similar to that for alicyclic alkanes. Cyclopentane, for instance, yields methane, ethane, propane, ethylene, propylene, cyclopentadiene, and hydrogen at 575°C. Analogous to cracking of alicyclic alkanes, the reaction proceeds by abstraction of a hydrogen atom followed by p scission. The cyclopentyl radical may undergo successive hydrogen abstractions to form cyclopentadiene. 

The principal source of toluene is catalytic reforming of refinery streams. This source accounts for ca 79% of the total toluene produced. An additional 16% is separated from pyrolysis gasoline produced in steam crackers during the manufacture of ethylene and propylene. The reactions taking place in catalytic reforming to yield aromatics are dehydrogenation or aromatization of cyclohexanes, dehydroisomerization of substituted cyclopentanes, and the cyclodehydrogenation of paraffins. The formation of toluene by these reactions is shown. 

Photolysis of cyclohexanone gives rise to carbon monoxide, ethylene, propylene (1), cyclopentane, 1-pentene (3), and 5-hexenal (29). Cyclo-hexenyl cyclohexanone, water, and a polymer have also been reported as products, especially when the photolysis is conducted in the temperature range from 100°-300° in the presence of short wavelength radiation (3). At 3130 A. and over the temperature range of 100°-300° the ketone that is decomposed is almost fully accounted for in the products (5) and the stoichiometry of the products fits the eq. 15-18 (3,27) ... 

The photolysis of cyclobutanone in the presence of 20- to 50-fold excess of ethylene has been reported (17). In this instance various five-carbon olefins but not cyclopentane are said to be observed among the products. The hydrocarbons are believed to be formed by a reaction between a tri-... 

The aminolyses of the carbonates derived from cyclopentane-1,2-diol (38) and cyclohexane-1,2-diol (39) by hexylamine at 70 °C were much slower than that of ethylene carbonate, the latter (39) being about twice as reactive as the former (38). Computational calculations confirmed that ring strain was the main determining factor.40... 

Figure 4.4 shows that accumulation of cyclopentene as an intermediate product increases in the initial period only and reaches its maximum when accumulation and consumption rates equalize. Further on, cyclopentadiene yield is equalized with increasing conditional contact time r (r = l/u where v is the liquid cyclopentane volume rate). For example, at 600 °C cyclopentene and cyclopentadiene yields equaling 10.5% and 5%, respectively, at 54.35% selectivity are reached at r = 1.66h. The rates of cyclopentene and cyclopentadiene synthesis increase first and reach their maxima at the inflection point. Cyclopentene, cyclopentadiene, methane, ethylene, carbon dioxide and unidentified hydrocarbons in the amount about 5% are synthesized in the reaction. 

Cyclisation of the organolithium 247 formed from the selenide 246 is unfavourable because it would generate a three-membered ring. But in the presence of ethylene, an intermolecular carbolithiation provides an unusual route to a primary organolithium, giving the cyclopentane 248.128... 

Rates of the losses of methyl and methane from the molecular ion of methylcyclopentane have been determined over the time range 40 ps to microseconds [288]. The loss of ethylene from methylcyclopentane and decompositions of methylcyclohexane were also investigated. With support from I3C labelling, it was suggested that at times shorter than 1 ns, methyl was lost from the intact cyclopentane ion, but that at longer times ring opening preceded the decomposition. 

Products formed by the reaction of cyclopentane with 1, 2 or 3 molecular proportions of ethylene were the chief products of the reaction of approximately equimolar amounts of the cycloalkane and the olefin under the standard conditions (Expt. 8). 

Cyclopentan (l/ ,2/ ,3S )-Allyl-3-ethoxycarbonyl-4,4-ethylen-dioxy-l-nitrooxy- E16c, 33 (0-S02-R -> o-no2)... 

When isopropylidenecyclopropane (29a equation 10) or diphenylmethylenecyclopropane (29b) is used, the codmerizations with alkenes such as ethylene, styrene or norbomene giving alkylidene-cyclopentanes are achieved under mild conditions in more than 75% yields. ... 

Relatively little work has been done on the pyrolyses of cyclopentane and the higher cyclic paraffins, and the nature of the reactions has not been established. Cyclopentane decomposes by two processes, giving (a) cyclopentadiene and hydrogen probably by way of cyclopentene and (b) propene and ethylene (ring cleavage), viz. 

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