2- Butene reaction with carbon atoms

MEK is a colorless, stable, flammable Hquid possessing the characteristic acetone-type odor of low molecular weight aUphatic ketones. MEK undergoes typical reactions of carbonyl groups with activated hydrogen atoms on adjacent carbon atoms, and condenses with a variety of reagents. Condensation of MEK with formaldehyde produces methylisopropenyl ketone (3-methyl-3-buten-2-one) ... 

Butene. Commercial production of 1-butene, as well as the manufacture of other linear a-olefins with even carbon atom numbers, is based on the ethylene oligomerization reaction. The reaction can be catalyzed by triethyl aluminum at 180—280°C and 15—30 MPa ( 150 300 atm) pressure (6) or by nickel-based catalysts at 80—120°C and 7—15 MPa pressure (7—9). Another commercially developed method includes ethylene dimerization with the Ziegler dimerization catalysts, (OR) —AIR, where R represents small alkyl groups (10). In addition, several processes are used to manufacture 1-butene from mixed butylene streams in refineries (11) (see BuTYLENEs). 

The first example of chemically induced multiplet polarization was observed on treatment of a solution of n-butyl bromide and n-butyl lithium in hexane with a little ether to initiate reaction by depolymerizing the organometallic compound (Ward and Lawler, 1967). Polarization (E/A) of the protons on carbon atoms 1 and 2 in the 1-butene produced was observed and taken as evidence of the correctness of an earlier suggestion (Bryce-Smith, 1956) that radical intermediates are involved in this elimination. Similar observations were made in the reaction of t-butyl lithium with n-butyl bromide when both 1-butene and isobutene were found to be polarized. The observations were particularly significant because multiplet polarization could not be explained by the electron-nuclear cross-relaxation theory of CIDNP then being advanced to explain net polarization (Lawler, 1967 Bargon and Fischer, 1967). 

For trichloroethene (TCE), the stoichiometric amount of iron and the effect of different preparations determine the outcome of the several competing reactions. Coupling products such as butenes, acetylene and its reduction products ethene and ethane, and products with five or six carbon atoms were formed (Liu et al. 2005). Although a held-scale application successfully lowered the concentration of TCE, there was evidence for the formation of the undesirable di-l,2-dichloroethene and 1-chloroethene (vinyl chloride) in the groundwater (Quinn et al. 2005). 

Table I gives the compositions of alkylates produced with various acidic catalysts. The product distribution is similar for a variety of acidic catalysts, both solid and liquid, and over a wide range of process conditions. Typically, alkylate is a mixture of methyl-branched alkanes with a high content of isooctanes. Almost all the compounds have tertiary carbon atoms only very few have quaternary carbon atoms or are non-branched. Alkylate contains not only the primary products, trimethylpentanes, but also dimethylhexanes, sometimes methylheptanes, and a considerable amount of isopentane, isohexanes, isoheptanes and hydrocarbons with nine or more carbon atoms. The complexity of the product illustrates that no simple and straightforward single-step mechanism is operative rather, the reaction involves a set of parallel and consecutive reaction steps, with the importance of the individual steps differing markedly from one catalyst to another. To arrive at this complex product distribution from two simple molecules such as isobutane and butene, reaction steps such as isomerization, oligomerization, (3-scission, and hydride transfer have to be involved.

The isopentene produced will either be protonated or be added to another carbenium ion. With a butyl cation, this would lead to a nonyl cation. The resultant carbenium ion fragment can accept a hydride and form a product heptane, or it can possibly add a butene to form a Cn cation. With hydride transfer, another alkane with an odd number of carbon atoms is produced. Just this example is sufficient to show the huge variety of possible reactions. By means of gas chromatographic analysis, Albright and Wood (82) found about 100-200 peaks in the C9-C16 region, regardless of the alkene and acid employed. A similar number of products can be observed for solid acid-catalyzed alkylation. 

Somewhat analogous reactions would be expected for the reaction of ethylene with 02 ions but the observed reaction rate is lower than for propene, suggesting that the reaction pathway may be controlled by the C—H bond energies. For reactions of propane and 1-butene with 02, oxygenated compounds of the same carbon number as the reactants were produced. The initial step is thought to involve a hydrogen atom abstraction from a secondary carbon atom. 

Cycloalkanes possessing a tertiary carbon atom may be alkylated under conditions similar to those applied for the alkylation of isoalkanes. Methylcyclopentane and methylcyclohexane were studied most.5 Methylcyclopentane reacts with propylene and isobutylene in the presence of HF (23-25°C), and methylcyclohexane can also be reacted with isobutylene and 2-butene under the same conditions.20 Methylcyclopentane is alkylated with propylene in the presence of HBr—AlBr3 (—42°C) to produce l-ethyl-2-methylcyclohexane.21 C12H22 bicyclic compounds are also formed under alkylation conditions.21 22 Cyclohexane, in contrast, requires elevated temperature, and only strong catalysts are effective. HC1—AICI3 catalyzes the cyclohexane-ethylene reaction at 50-60°C to yield mainly dimethyl- and tetra-methylcyclohexanes (rather than mono- and diethylcyclohexanes). The relatively weak boron trifluoride, in turn, is not active in the alkylation of cyclohexane.23... 

Disubstituted furans (130) can be obtained by treatment of j8-alkoxy- and j8-arylthio-a,j8-unsaturated ketones, for example 3-methoxy-l-phenyI-2-buten-l-one (128) or 3-ethylthio-l-phenyl-2-buten-l-one (129), with dimethylsulfonium methylide (79JHC815, 69TL679). The possible reaction pathway (Scheme 27) shows the initially formed epoxides as rearranging by ring opening at the tertiary epoxide carbon atom. 

Commercial production of 1-butene, as well as the manufacture of other linear o-oleJins with even carbon atom numbers, is based on (lie ethylene oligomerization reaction. 

Reactions of the recoil C1] with several olefins have been studied, including ethylene, propylene, cyclopentene, and cfs-butene-2, as well as with several paraffins. The type of products observed indicated the existence of several general modes of interaction, such as CH bond insertion, interactions with CC double bonds, formation of methylene-C11. The most important single product in all systems is acetylene, presumably formed by CH insertion and subsequent decomposition of the intermediate. Direct interaction with double bonds is shown by the fact that, for example, in the case of propylene, yields of stable carbon atom addition products were significantly higher than in the case of propane. The same was true for ethylene and ethane. 

Predict the products formed by reaction of ground-state carbon atoms with rw-2-butene and with trans-2-butene. 

The relative position of L with respect to S and of H with respect to Z can be decided, for instance, by hydroformylation of (Z)-2-butene, which yields only one aldehyde that is chiral. When the catalyst is optically active, the predominating antipode in the reaction product indicates the face of the unsaturated carbon atoms preferentially attacked by CO and therefore the more stable transition state (Fig. 8) (that is, on the assumption that the difference in the free energy of the transition state mainly depends on steric interactions, the transition state in which such steric interactions are smaller). 

As it is well known, acyloxy, alkoxy, or phenoxy groups connected to sp2-hybridized carbon atoms in alkenes or aromatics are unreactive to nucleophilic substitution. However, after alkene ozonolysis such groups become attached to sp3-hybridized carbon atoms and become reactive. It was shown <1989TL1511> that such substitutions have to be carried out at 40 °C when they compete with thermolytic reactions of the ozonides, lowering the yields. However, if 2,3-dichloropropene and as- or /ra/rt-1,2,4-trichloro-2-butene are ozonized, one obtains stable ozonides 68a-70... 

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