Heptenes, reaction

As our first illustration we consider the co-dimerization of propene and butene to produce heptenes (Reaction 1). This reaction is accompanied by two competing, undesirable, reactions dimerization of propene to hexene (Reaction 2), and dimerization of butene to octene (Reaction 3). The second reaction proceeds extremely rapidly and in order to suppress the formation of hexenes we should have progressive injection of propene into the reactor with all the butenes at the beginning of the operation, as is shown in Fig. 22 (Trambouze et al., 1988). 

RCH=CH2decreasemonotonically from > 0.90 for propene and 1-butene to0.21 to0.39 for 1-octene. H-atom abstraction from the CH2 groups in the 1-alkenes is expected to account for an increasing fraction of the overall OH radical reaction as the carbon number of the 1-alkenes increases, with about 15% of the 1-heptene reaction being estimated to proceed by H-atom abstraction from the secondary CH2 groups. The propene-OH reaction mechanism is shown in Figure 6.14. 

The ozonolysis of mixtures of 3-hexene and 4-octene does indeed give 3-heptene ozonide, in addition to the ozonides of 3-hexene and 4-octene. Experiments were then designed to determine the eflFect of olefin geometry in the 3-hexene and 4-octene on the 3-heptene ozonide cis-trans ratio. The yields and cis-trans ratios of 3-heptene ozonide from 10 different sources are given in Table I. In these experiments the pure 3-heptene reactions were carried out at l.OM, while the pure 3-hexene runs were made at 0.5M. Where mixtures of olefins were used, the solution was 0.5M in each olefin. In the olefin-aldehyde experiments the concentrations were 0.5 and 0.25M for olefin and aldehyde, respectively. 

Figure IV-E-2. Arrhenius plot for the OH + 2-pentenal, 2-hexenal, and 2-heptenal reactions.

The sample solution to Problem 17 16(a) showed the prepara tion of 3 methyl 3 heptene by a Wittig reaction involving the ylide shown Write equations showing the formation of this ylide beginning with 2 bromobutane... 

Miller et al. [9] hypothesized rules on the regioselectivity of addition from the study of the base-catalyzed addition of alcohols to chlorotnfluoroethylene. Attack occurs at the vinylic carbon with most fluorines. Thus, isomers of dichloro-hexafl uorobutene react with methanol and phenol to give the corresponding saturated and vinylic ethers The nucleophiles exclusively attack position 3 of 1,1-dichloro-l,2,3,4,4,4-hexafluoro-2-butene and position I of 4,4-dichloro-l,l,2,3,3,4-hexafluoro-1-butene [10]. In I, l-dichloro-2,3,3,4,4,4-hexafluoro-l-butene, attack on position 2 is favored [J/] (equation 5) Terminal fluoroolefms are almost invariably attacked at tbe difluoromethylene group, as illustrated by the reaction of sodium methoxide with perfluoro-1-heptene in methanol [/2J (equation 6). 

Another interesting fact to be noted is that the bicyclic enamine (87) and its pyrrolidine analogue failed to undergo reduction with 98% formic acid, whereas the pyrrolidine enamine of 2-bicyclo[2.2.1]hepten-5-carboxalde-hyde (94), which exists largely in the transoid form (49), was readily reduced to (95). However, the saturated amine-substituted norbornane can be obtained directly from norbornanone under the more vigorous conditions of the Leuckart reaction (49a). 

The reaction of morpholine with tricyclo[2.2.1.0 ]hcptan-3-one (35) and with 5-bicyclo[2.2.1]hepten-2-one (36) does not proceed in the... 

Substituted TMM complexes also cycloadd to aldehydes in the presence of a tin cocatalyst such as MesSnOAc and MesSnOTs [31]. Reaction of 2-heptenal with methyl precursor (6) gave a mixture of methylenetetrahydrofurans (68) and (69). This regioselectivity is reversed with 10-undecenal and methyl precursor (5), where adduct (70) now predominates over (71). As in the carbocyclic system, the phenylthio group also functions as a regiocontrol element in reaction with cyclohexyl aldehyde. The initially formed adduct (72) eliminates the element of thio-phenol on attempted allyl rearrangement, and the overall process becomes a cycloaddition approach to furans (Scheme 2.21) [20]. 

DEPT-NMR spectrum. 6-methyl-5-hepten-2-ol, 451 Detergent, structure of, 1065 Deuterium isotope effect, 386-387 El reaction and, 392 E2 reaction and, 386-387 Dewar benzene. 1201 Dextromethorphan, structure of, 294 Dextrorotatory, 295 Dextrose, structure of. 973 Dialkylamine, pKa of, 852 Diastereomers, 302-303 kinds of, 310-311 Diastereotopic (NMR), 456... 

Hydrazoic acid reaction with cyclobu-tanecarboxyhc acid, 47, 28 Hydrogenation of t butylazidoacetate to glycme ( butyl ester, 46,47 Hydrogen bromide 46, 43 reaction with y butyrolactone, 46, 43 Hydrogen fluoride anhydrous, precautions in use of, 46, 3 in preparation of mtromum tetra-fluoroborate 47, 57 reaction with benzoyl chloride, 46,4 with boron tnfluonde in conversion of p cymene to m cymene, 47, 40 in bromofluorination of 1 heptene, 46, 11... 

The enol ether double bond contained within the ds-fused dioxa-bicyclo[3.2.0]heptene photoadducts can also be oxidized, in a completely diastereoselective fashion, with mCPBA. Treatment of intermediate XXII, derived in one step from a Patemo-Buchi reaction between 3,4-dimethylfuran and benzaldehyde, with mCPBA results in the formation of intermediate XXIII. Once again, consecutive photocycloaddition and oxidation reactions furnish a highly oxygenated system that possesses five contiguous stereocenters, one of which is quaternary. Intermediate XXIII is particularly interesting because its constitution and its relative stereochemical relationships bear close homology to a portion of a natural product known as asteltoxin. 

Benzo-3-thiatricyclo[4.1.0.02-7]heptene (I, X = H) is a valene -type valence isomer of 2 and 3 however, 1 isomerizes to 3 in photochemical and silver(I)-promoted reactions.75 However. when 1 is heated in carbon tetrachloride at 150°C 3 is not produced but instead the isomeric 1,2-disubstituted 2a,7b-dihydrobenzo[f>]cyclobuta[r/]thiophene. When a rhodium(I)... 

Azetidines 19 and 21 resulted (81M12) from photocycloaddition of 1,3-dimethyl-6-azathymine 17 with 1-heptene. The reaction could also be extended to the irradiation of 17 with 2-heptene, cyclohexene, and 1-, 3-, or 4-methylcyclohexene to give 20 and 22, respectively (87MI2). Photocycloaddition of dihalomaleimides 23 with 18 gave tricyclic 24 (83AG156) (Scheme 6). 

Phenyl-V-heptene Typical Procedure for the Reaction of RCu BE, with Allylic Halides and Allylic Alcohols 11 ... 

The lithium enolates of cyclopentanone and cyclohexanone undergo addition-elimination to the 2,2-dimethylpropanoic acid ester of ( )-2-nitro-2-hepten-l-ol to give 2-(l-butyl-2-nitro-2-propenyl)cycloalkanones with modest diastereoselection. An analogous reaction of the enolate ion of cyclohexanone with the 2,2-dimethylpropanoic acid ester of (Z)-2-nitro-3-phenyl-2-propenol to give 2-(2-nitro-l-phenyl-2-propenyl)cyclohexanones was also reported. The relative configuration of these products was not however determined6. 

B. (Z)-l-Iodo-l-heptene.2 A solution of 8.52 g of (112 mmol) of borane-dimethylsulfide complex (Note 13) in 100 mL of ether is added to a flame-dried, three-necked, 300-mL, round-bottomed flask equipped with stirbar, temperature probe, and N2 inlet. The solution is cooled to 5°C with an ice-bath. Cyclohexene (18.4 g, 224 mmol) (Note 14) is then added by syringe over 10 min while keeping the temperature below 15°C. The mixture is stirred at 5°C for 15 min. A white solid precipitates either towards the end of the addition or during the subsequent stirring period. The reaction mixture is allowed to warm to room temperature and is stirred for 1 hr. The non-homogeneous solution is cooled to 2-3°C... 

An example of the Diels Alder reaction of furans is the cycloaddition of 31 with 4,4-diethoxybut-2-ynal (32) which acts as an acetylenedicarbaldehyde synthon to afford 7-oxabicyclo [2.2.1]heptene derivatives [29] which were then converted into substituted cyclohex-l-ene-l,6-dicarbaldehydes by a four-step procedure (Scheme 2.14). 

Oxepanes have been obtained by the iodoetherification of unsaturated alcohols using bis(5 / -collidine)iodine(I) hexafluorophosphate <96JOC5793>. Thus 6-hepten-l-ol affords 2-iodomethyloxepane in 95% yield. A similar reaction with, for example, (3Z,6Z)-3,6-octadien-l-ol affords 2-(iodomethyl)-2-methyl-4-oxepane. 

With the growing interest for the polynorbomene, photoresist polymer, and cyclic olefin copolymer, the synthesis norbornene or bicyclo[2,2,l]-2-heptene (NBN) has drawn significant attention because it is one of the most important precursor for these materials. Norbornene is produced by the reaction between ethylene and cyclopentadiene (CPD) via the Diels-Alder condensation process at elevated temperature and pressure [1,2]. 

It also explains the /Z selectivity of products at low conversions (kinetic ratio. Scheme 19). In the case of propene, a terminal olefin, E 2-butene is usually favoured (E/Z - 2.5 Scheme 19), while Z 3-heptene is transformed into 3-hexene and 4-octene with EjZ ratios of 0.75 and 0.6, respectively, which shows that in this case Z-olefins are favoured (Scheme 20). At full conversion, the thermodynamic equilibriums are reached to give the -olefins as the major isomers in both cases. For terminal olefins, the E olefin is the kinetic product because the favoured pathway involved intermediates in which the [ 1,2]-interactions are minimized, that is when both substituents (methyls) are least interacting. In the metathesis of Z-olefins, the metallacyclobutanes are trisubstituted, and Z-olefins are the kinetic products because they invoke reaction intermediates in which [1,2] and especially [1,3] interactions are minimized. 

It is possible to synthesize cobalt complexes which are soluble in polyethylene glycols and not in. solvents like hexane, hexene, heptenal etc. Ritter et al. (1996) have reported the oxo reaction of 1-hexene in such a system. 

Because aldrin contains the bicyclo-(2.2.1)-heptene ring structure, it reacts typically with phenyl azide to form a phenyldihydrotriazole derivative. This reaction is of importance in that it provides the basis for an analytical method for determining aldrin (discussed more fully in 2). 

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