2-Methyl-2-methylbutene

Consider the spectral data for 2-methyl-2-methylbutene (Figs. 10.6 and 10.7). 

The IR spectrum and NMR spectral data for 2-chloro-2-methylbutane, 2-methyl-2-butanol, 2-methyTl-butene, and 2-methyl-2-methylbutene are provided in Figures 14.7,14.8,14.5, 14.6, and 10.4r-10.7, respectively. 

In the 1960s, after Kennedy and Thomas [25] had established the isomerisation polymerisation of 3-methylbutene-l, this became a popular subject. From Krentsel s group in the USSR and Aso s in Japan there came several claims to have obtained polymers of unconventional structure from various substituted styrenes by CP. They all had in common that an alleged hydride ion shift in the carbenium ion produced a propagating ion different from that which would result from the cationation of the C C of the monomer and therefore a polymer of unconventional structure the full references are in our papers. The monomers concerned are the 2-methyl-, 2-isopropyl-, 4-methyl-, 4-isopropyl-styrenes. The alleged evidence consisted of IR and proton magnetic resonance (PMR) spectra, and the hypothetical reaction scheme which the spectra were claimed to support can be exemplified thus ... 

Synonyms EINECS 209-249-1 Isopentene Isopropylethene Isopropylethylene a-Isoamylene 2-Methyl-3-butene 3-Methylbutene UN 2561 Vinyl isopropyl. 

Doering and Prinzbach20 photolyzed CH2N2 in the presence of 2-methylpropene 1-14C in the liquid phase and in the gas phase at 400 mm. The product ratios (Table II) in the liquid were quite similar to the high pressure values of Frey and Knox et al., although Doering and Prinzbach also report no 3-methylbutene-l. The chief object of this work was to study the mechanism of the insertion reaction of methylene into CH bonds. The product 2-methyl-butene-l, which is formed entirely by insertion and not by isomerization, was separated from the reaction... 

Condensation of salicylaldehydes with 2-chloro-3-formylbutene and analogs gave 2-methylenechromcnc derivatives.227 The direct reaction of salicylaldehyde with 2-methyl-2-chlorobutane or 2-methylbutene with catalysts to give 2,2,3-trimethylchromene is reported in a patent228 The structure of the products from salicylaldehyde and dipheny-lenes229,230 has been revised, (see Section V,B).231... 

A solution of 6.0 mL of borane-methyl sulfide complex (10M BH3 in methyl sulfide) in 45 mL THF was placed in a He atmosphere, cooled to 0 °C, treated with 12.6 g of 2-methylbutene, and stirred for 1 h while returning to room temperature. To this there was added a solution of the impure 3,4-diethoxy-5-methylthiostyrene in 25 mL THF. This was stirred for 1 h during which time the color deepened to a dark yellow. The excess borane was destroyed with about 2 mL MeOH (all this still in the absence of air). There was then added 11.4 g elemental iodine followed by a solution of 2.4 g NaOH in 30 mL of boiling MeOH, added over the course of 10... 

The amides of alkali and alkaline-earth metals catalyse hydrogen exchange in hydrocarbons even in the absence of liquid ammonia. For example, the heterogeneous deuterium exchange of benzene and 2-methylbutene-l occurs with a considerable velocity on solid KND2 and Ca(ND2)2 at 70°. This gives rise to the isomerization of 2-methyl-butene-1 to 2-methylbutene-2 (Shatenshtein et al., 1958a). 

This conclusion is supported by observations of the isomerization of unsaturated hydrocarbons catalysed by potassium amide not only in ammonia solution (Shatenshtein and Vasil eva, 1954 Shatenshtein et al., 1954) but also by solid amides of alkali and alkaline-earth metals (Shatenshtein et al., 1958a). For example, diallyl rearranges to dipropenyl, pentene-1 to pentene-2, and 2-methylbutene-l to 2-methyl-butene-2. Subsequently, a further number of examples of isomerization... 

SYNS tert-AMYLENE ISOPENTENE ISOPENT-ENES pOT) METHYLBUTENE 2-METHYL-BUTENE... 

METHYLBUTAN-l-OL see IHPOOO 3-METHYLBUTAN-3-OL see PBVOOO 3-METHYL-l-BUTANOL (CZECH) see IHPOOO 3-METHYLBUTANOL NITRITE see IMBOOO 3-METHYL-2-BUTANONE see MLA750 3-METHYL BUTAN-2-ONE (DOT) see MLA750 METHYLBUTENE see IHR220 2-METHYLBUTENE see IHR220... 

Fig. 5.1. Chromatograms of products of catalytic cracking (A) without reactor and (B) with reactor. Sorbent, 11% quinoline on refractory brick temperature, 25 C column length, 10.5 m. Peaks 1 = propane 2 = propylene 3 = isobutane 4 = n-butane 5 = isobutene 6 = butene-1 7 = rmns-butene-2 8 = cis-butene-2 9 = isopentane 10 = 3-methylbutene-l 11 = n-pentane 12 = pentene-1 13 = 2,2-dimethylbutene 14 = 2-methylbutene-l 15 = tnms-pentene-2 16 = cfsi)entene-2 17 = 2-methyl-butene-2 18 = 2,3-dimethylbutane 19 = 2-methylpentane 20 = 3-methylpentane 21 = 3-methylpen-tene-1 22 = 4-methylpentene-l 23 = c -4-methylpentene-2 24 = cyclopentane 25 = 2,3-dimethyl-butene-1 26 = fmns-4-methylpentene-2 27 = w-hexane 28 = cyclopentene 29 = 2-methylpentene-l 30 = hexene-1 31 = 2,4-dimethylpentane 32 = cis-hexene-3 33 = tnms-hexene-3 34 = 2-ethylbu-tene-1 35 = trans-hexene-2 36 = methylcyclopentane 37 = cis-methylpentene-2 38 = 2-methylpen-tene-2 39 = pisns-3-methylpentene-2 40 = methylcyclopentene-4 41 = 4-methylcyclopentene 42 = cw-3-methylpentene-2 43 = 2,3-dimethylpentane 44 = 2-methylheptane 45 = 2,3-dimethylbutene-2 46 = methylheptane 47 = cyclohexane 48 = C, olefin. Reprinted with permission from ref. 1.

The Claisen rearrangement has not proved of value for obtaining 2-(3-methylbut-2-enyl)phenol. Thus, 3-methylbuten-2-yl 4-methylphenyl ether at 220°C in dimethylpyridine gave an unstated yield of 4-methyl-2-(1,2-dimethylprop-2-enyl)phenol (ref. 7). 

Claisen had reported that the proportion of C- to O-alkylation could be greatly enhanced by the use of sodium phenoxides in benzene suspension and indeed this method has been beneficially employed for o-C-isoprenylation. In a general procedure (ref.9), an ethereal solution of the phenol (0.05 mole), was treated with metallic sodium (0.2 mole) and after 1.5 hours the prenyl chloride (RCI) was introduced. Upon refluxing for 10 hours, removal of excess sodium and acidic work-up, monohydric phenols afforded yields from 66-90%. For example, 2-methylphenolwith3-methylbuten-2-ylchloridegave2-methyl-6-(3-methylbuten-2-... 

Orcinol upon treatment dropwise with 2-methyl-3-buten-2-ol in warm aqueous formic acid at 80°C and reaction for 1 hour afforded 5-methyl-4-(3-methylbuten-2-yl)resorcinol in low yield while from the filtrate of the reaction mixture, the isomeric compound, 5-methyl-2-(3-methylbuten-2-yl)resorcinol was isolated as well as a bis-prenyl compound by chromatographic purification (ref.16). 

An example illustrating that the same products are formed from isomeric branched-chain olefins of different double-bond location is shown by hydroformylation of 2-methylbuten -2, 3-methylbutene-l, or 2-methyl-buteno-1 ... 

A solution of 10 mL of borane-methyl sulfide complex (10 M BH3 in methyl sulfide) in 75 mL THF was placed in a He atmosphere, cooled to 0 °C, treated with 21 mL of 2-methylbutene, and stirred for 1 h while returning to room temperature. This was added directly to the crude 4-... 

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