Mixed 2-Pentenes

A second route based on olefin disproportionation was developed by Phillips Petroleum (131). Here isobutylene reacts with propylene to form isoamylenes, which are dehydrogenated to isoprene. 2-Butene can be used in place of propylene since it also yields isoamylene and the coproduct propylene can be recycled. Use of mixed butylenes causes the formation of pentenes, giving piperjlene, which contaminates isoprene. 

Two approaches for the synthesis of allyl(alkyl)- and allyl(aryl)tin halides are thermolysis of halo(alkyl)tin ethers derived from tertiary homoallylic alcohols, and transmetalation of other allylstannanes. For example, dibutyl(-2-propenyl)tin chloride has been prepared by healing dibutyl(di-2-propenyl)stannane with dibutyltin dichloride42, and by thermolysis of mixtures of 2,3-dimethyl-5-hexen-3-ol or 2-methyl-4-penten-2-ol and tetrabutyl-l,3-dichlorodistannox-ane39. Alternatively dibutyltin dichloride and (dibutyl)(dimethoxy)tin were mixed to provide (dibutyl)(methoxy)tin chloride which was heated with 2,2,3-trimethyl-5-hexen-3-ol40. 

Trimethyl-l-pentene (TMP) (2 ml) was mixed with MeX (5 ml) and desired amounts of alkylaluminum and f-BuX solutions were added. In a similar study, 2 ml TMP were mixed with 5 ml MeBr and 0.1 ml of a solution of AlBr3 MeBr complex in MeBr (10 vol.%) was added at -80 °C. The reaction was stopped after 20 mins, and the products separated and analyzed using Kennedy and Rengachary s method11J. 

We initially tested Candida antarctica lipase using imidazolium salt as solvent because CAL was found to be the best enzyme to resolve our model substrate 5-phenyl-l-penten-3-ol (la) the acylation rate was strongly dependent on the anionic part of the solvents. The best results were recorded when [bmim][BF4] was employed as the solvent, and the reaction rate was nearly equal to that of the reference reaction in diisopropyl ether. The second choice of solvent was [bmim][PFg]. On the contrary, a significant drop in the reaction rate was obtained when the reaction was carried out in TFA salt or OTf salt. From these results, we concluded that BF4 salt and PFg salt were suitable solvents for the present lipase-catalyzed reaction. Acylation of la was accomplished by these four enzymes Candida antarctica lipase, lipase QL from Alcaligenes, Lipase PS from Burkholderia cepacia and Candida rugosa lipase. In contrast, no reaction took place when PPL or PLE was used as catalyst in this solvent system. These results were established in March 2000 but we encountered a serious problem in that the results were significantly dependent on the lot of the ILs that we prepared ourselves. The problem was very serious because sometimes the reaction did not proceed at all. So we attempted to purify the ILs and established a very successful procedure (Fig. 3) the salt was first washed with a mixed solvent of hexane and ethyl acetate (2 1 or 4 1), treated with activated charcoal and passed into activated alumina neutral type I as an acetone solution. It was evaporated and dried under reduced... 

A second set of experiments were performed after the treatment of 10 or 11 with added pyridinium ion whereby the mixed quinuclidine pyridine halonium ion (12) that was created in situ was subsequently treated with a varying [4-penten-l-ol] or [4-hexene-l-ol] in the presence of a varying [pyridine]. Inspection of the process shown in Figure 8 suggests that, once having made 12... 

Liu and Zhong introduced a number of QSPR models based on molecular connectivity indices [151, 152], In a first iteration, the researchers developed polymer-dependent correlations descriptors were calculated for a set of solvents and models were developed per polymer type [151], Polymer classes under consideration were polystyrene, polyethylene, poly-1-butene, poly-l-pentene, poly(4-methyl-l-pentene), polydimethylsiloxane, and polyisobutylene. As the authors fail to provide any validation for their models, it is difficult to asses their predictive power. In a subsequent iteration and general expansion of this study, mixed and therefore more general models based on the calculated connectivity indices of both solvent and polymers were developed. While it is unclear from the paper which polymer representation was used for the calculation of the connectivity indices, the best regression model (eight parameter model) yields only acceptable predictive power (R = 0.77, = 0.77, s = 34.47 for the training set, R = 0.75... 

THF (5 g) mixed with 0.1 ml 10 NHC1 and added slowly to 5 g of titanium isopropoxide with fast stirring. This sol was then mixed with a 10 wt% solution of triethoxysilane capped PF or PEK in THF. The final solution was cast into poly(4-methyl-pentene) Petri dishes and covered for drying and curing at 60 °C for 24 h. Films were then removed and annealed at 200 °C for 15 min... 

When two polymeric systems are mixed together in a solvent and are spin-coated onto a substrate, phase separation sometimes occurs, as described for the application of poly (2-methyl-1-pentene sulfone) as a dissolution inhibitor for a Novolak resin (4). There are two ways to improve the compatibility of polymer mixtures in addition to using a proper solvent modification of one or both components. The miscibility of poly(olefin sulfones) with Novolak resins is reported to be marginal. To improve miscibility, Fahrenholtz and Kwei prepared several alkyl-substituted phenol-formaldehyde Novolak resins (including 2-n-propylphenol, 2-r-butylphenol, 2-sec-butylphenol, and 2-phenylphenol). They discussed the compatibility in terms of increased specific interactions such as formation of hydrogen bonds between unlike polymers and decreased specific interactions by a bulky substituent, and also in terms of "polarity matches" (18). In these studies, 2-ethoxyethyl acetate was used as a solvent (4,18). Formation of charge transfer complexes between the Novolak resins and the poly (olefin sulfones) is also reported (6). 

Formulation of Resist Solutions. Forty grams of a Novolak resin was mixed with 10 g of the photoactive compound, and dissolved in 100 g of bis-2-methoxy-ethylether. After wafers were spin-coated, the samples were immediately placed on a hot plate at 82 C for 14 min. The formulation procedure of a composite resist of poly (2-methyl-1-pentene sulfone) in the Novolak resin is as follows the polysulfone was mixed with the resin (13 wt% solid), and then dissolved in 2-methoxyethyl acetate the films were spin-coated onto silicon wafers, and then baked at 100°C for 20 min prior to electron beam exposure. 

For further enhancement of electron beam sensitivity, the chlorinated Novolak resin was studied using poly (2-methyl-1-pentene sulfone) as a dissolution inhibitor. The chlorinated Novolak resin mixed well with the polysulfone, and there was no phase separation observed when the films were spin-coated. With 13 wt% of the polysulfone, the chlorinated Novolak resist cast from a cellosolve acetate solution yielded fully developed images with R/Ra = 9.2 after exposure to 2 / 2. It gave fully developed images with R/R0 = 3.2 at a dose of 1 / 2, as shown in Figure 3. There are some problems with this resist system some cracking of the developed resist images... 

The compound (dppe)PtMe(OMe),256 which is prepared by a metathesis reaction involving NaOMe and (dppe)PtMe(Cl) in a mixed benzene/methanol solvent system (dppe = bis(l,2-di-phenylphosphino)ethane), does not react with ethylene or pentene but does react with activated alkenes such as acrylonitrile, methylacrylate and fluoroalkenes. The reaction involving tetrafluoro-ethylene has been shown to give (dppe)PtMe(CF2CF2OMe), providing the first example of an alkene insertion into an M—OR bond.256 Interestingly, no insertion into the Pt—Me bond was observed. 

MIXED HIGHER ORDER CYANOCUPRATE-INDUCED EPOXIDE OPENINGS 1-BENZYLOXY-4-PENTEN-2-OL... 

Dimethyl- 1-phenyl-1 -penten-3-one (product of mixed aldol condensation)... 

Kinetic Measurements. All experiments were conducted in a constant temperature oil bath controlled within 0.1°C. The stabilizer was dissolved in chlorobenzene in a volumetric flask of suitable volume, usually 100 ml., and placed in the bath. After about 7 minutes the volume was adjusted to about 95 ml., and 4-chloro-2-pentene was added from a pipet with swirling for 100 ml. of solution generally 2.00 ml. (average wt. 1.7958 grams) of chloride was added to give a 0.172N solution in chloride. The volume was adjusted quickly to nearly 100 ml. with chlorobenzene, and the contents were mixed thoroughly. Final adjustment to 100 ml. was made when thermal equilibrium was reached. 

Mixed Solvents Effect. Using mixed solvents can improve selectivity. For example, adding small amounts of water has improved the selectivity of furfural in separating C4 hydrocarbons (24). Baumgarten and Gerster (25) have studied how various solvents affect the selectivity of furfural for the pentane-pentene pair. They concluded that for only a few solvents some improvement was observed. The resulting selectivity lies between the selectivity of the pure solvents (see Table III). To avoid immiscibility at high solvent concentrations, a second solvent is sometimes added (25). 

This reaction is analogous to the preparation of bis(4-imino-2-pentanonato)copper(II) [bis(4-amino-3-penten-2-onato)copper(II)] described by Holtzclaw, Collman, and Alire, and it consists in mixing an ethanolic solution of the -keto imine ( -imino ketone) with an ammoniacal metal salt solution. Advantages of this technique are the simplicity of preparation and the fact that acetylacetone imide (4-imino-2-pentanone) can be purchased. The product is useful as a starting material in ligand-exchange reactions. 

Mercury. Upon mixing a solution of mercury (II) chloride in acetone with tetraen and penten in the same solvent, the initially gummy precipi-... 

The CHDs formed by intramolecular addition often eliminate water to give another of,)6-unsaturated ketone. For mesityl oxide (4-methyl-3-pentene-2-one), 22b, the influence of the reaction conditions on the product distribution was examined in detail [96]. Mixtures of four dimeric species were observed, resulting from initial 4,4 -coupling (24b-d), or from mixed 2,4 -coupling, 24a. Pinacol formation (2,2 -coupling) was not observed [Eq. (6)]. 

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