Methyl pentyl carbonate

C14H16 7-methyl-1 -isopropylnaphthalene 66577-17-1 555.15 45.453 1,2 27517 C14H19I03 p-iodobenzyl-4-methyl-2-pentyl carbonate 60075-70-9 419.65 36.221 2... 

In some cases, the molecule contains two or more complex substituents that have the same number of carbons in the longest chain, but they are different. An example is the three pentyl groups in 22. This compound is a tripentylico-sane, but the secondary substituents are different. At C7, there is a 1-methyl-pentyl, there is a 4-methylpentyl at C8, and a 3-methylpentyl group is at C8. In such cases, the rule states that priority for citation is given to the substituent that contains the lowest locant at the first cited point of difference— in this case, the 1-methylpentyl, followed by 3-methylpentyl, followed by 4-methylpentyl. The name of 22 is 7-(l-methylpentyl)-9-(3-methylpentyl)-8-(4-methylpentyl)icosane. 

As discovered by Natta, Pino and coworkers(16,17), isotactic polymerization of chiral -olefins is stereoselective (e.g., isotactic poly-(R,S)-3-methyl-1-pen-tene consists of enantiomeric macromolecules which can be partially resolved.) If one considers that the isotactic steric control arises from the enantiose-lectivity of the chiral catalytic sites toward the enantiotopic carbon of the monomer(7,11) then stereoselectivity simply means that the insertion is dia-stereoselective. In other words, the diastereotopic faces of the monomer must have a different reactivity in the insertion (Figure 3) Figure 4 shows the - G NM spectrum of isotactic poly-(R,S)-3-methyl-l-pen-tene obtained in the presence of 6TiCl3-Al( - CH3)3 (sample 8). The resonances at 13.2Zj, 13A57i 15 09 and 15.2 ppm are due to the 0113 s of 2 - - C-2,3-di-methyl-pentyl end groups formed in the initiation step(l8). 

Foods frequently contain saturated and unsaturated aliphatic ketones with between 3 and 17 carbon atoms in the molecule. These ketones are formed by several different mechanisms. Frequently occurring aliphatic ketones are methylketones. The most common methylketone is acetone (propanone, 8-46, = 0). Acetone is present, usually in small quantities, in all biological substrates, where it arises by decarboxylation of acetoacetic (3-oxobutanoic) acid. Acetoacetic acid is formed as an intermediate during degradation of fatty acids by -oxidation. Acetone in the skins of apples, for example, is produced from pyruvic acid via citramalic acid (Figure 8.16). The relatively large amount of acetone is generated by acetone-butanol fermentation (see Section 8.2.2.1.1). Many other saturated and unsaturated methylketones occur as odour-active components of essential oils. For example, a component of cinnamon and star anise essential oils is heptane-2-one, also known as methyl pentyl ketone (8-46, = 4). 

The enthalpy of formation of methyl n-pentyl ether is unavailable from experiment, but a value of —316 kJmoP is obtained from the linear regression analysis of the known enthalpies of formation of methyl n-alkyl ethers vs. the number of carbon atoms in the ethers . The methylene increment of —25.3 kJmoP for this homologous ether series is nearly identical to the methylene increment for n-alkanes. Because the experimental protodelithiation enthalpies for the two primary lithio ethers are identical, the methylene increment in that homologous series as calculated here is necessarily identical to that of the homologous methoxy ethers. As calculated from the methylene increment or from equation 16, the enthalpy of formation of 5-lithiopentyl methyl ether is ca —309 kJmol. ... 

In the previous example the elimination could occur only in the pentyl group because the other three substituents on the nitrogen are methyl groups, which do not have /3-carbons. However, if more than one of the alkyl groups bonded to the nitrogen is larger than methyl, then elimination can, in principle, involve any of these groups. 

Alkyl groups are named by replacing the -ane suffix of the alkane name with -yl. Methane becomes methyl ethane becomes ethyl. You may encounter the word amyl, which is an archaic term for a pentyl (five-carbon) group. 

Isopentyl group— An alkyl group with the molecular structure of -CH2CH2CH(CH3)2 and is identified as the pentyl derivative that has a methyl group (-CH3) branching from the end of a chain of four carbon atoms. 

Problem 18.3 (a) Carbon monoxide converts a sulfuric acid solution of each of the following into 2,2-dimethyibutanoic acid 2-methyl-2-butene, ferr-pentyl alcohol, neopentyl alcohol. Suggest a likely mechanism for this method of synthesizing carboxylic acids, (b) / Butyl alcohol and rec-butyl alcohol give the same product. What would you expect it to be ... 

The resorcinols used as starting materials in the present process are either resorcinol itself (III, R=H) or a 5-alkylresorcinol (III, R=alkyl). The alkyl group may have up to twelve carbon atoms and it may be either branched or straight-chained. Examples of such alkyl groups are methyl, ethyl, propyl, sec-butyl, pentyl, 1,1-dimethylbutyl, 1,2-dimethylbutyl, l-ethyl-2-methylpropyl, isohexyl, heptyl, 1-methylhexyl, 1,2-dimethylhexyl, 1,2-dimethylheptyl, 1-methyloctyl, and 1-methylnonyl. 

This list is exhaustive as far as non-carbon parent hydrides are concerned. A number of established shortened or entirely non-systematic names are also used for carbon-based hydrides methyl, ethyl, propyl, butyl, pentyl, hexyl, cyclohexyl, phenyl, naphthyl, etc. 

When the aryl ring was optimally substituted as in prochloraz (III), simple variations of the N-alkyl group (for example from propyl to isopropyl, butyl or pentyl), were permissible without much loss in activity as was substitution of either carbon atom of the ethyl portion of the aryloxyethyl group by a methyl group. In some cases the aryloxyethyl chain could be extended to aryloxypropyl without loss of activity, but this was not always true. 

In the 1950s, it was reported that the reaction of cyclopropane with lithium aluminum hydride gave tripropylaluminum. However, this result was not verified. The reaction of cyclopropane in the vapor phase with diborane to monoalkylcyclopropanes was shown to be fairly regioselective, the products being derived from addition of the hydride to the most-substituted carbon atom, and the boron to the least-substituted carbon atom. With butyl-, pentyl- and octylcyclopropanes after oxidative workup the linear primary alcohols 3 were obtained as the major products together with small quantities of the 2-methyl derivatives 4. 

Neo- refers to a substituent whose second-to-last carbon of the chain is trisubstituted (has three methyl groups attached to it). A neo-pentyl has five carbons total. 

Peptide synthesis /-Amyl chloroformate. Bis-(2,4-dinitrophenyl)carbonate. Bis-o-phenylene pyrophosphite. i-Butyl chloroformate. sec-Butyl chloroformate. /-Butyl chloroformate. /-Butyl 2,4,5-trichlorophenyl carbonate. CopoIy(ethylene-N-hydroxymaleimide). N,N-Diethyl-I-propynylamine. Di-(p-nitrophenyl)sulfate. Ethoxyacetylene. N-Ethoxycarbonyl-2-ethoxy-l,2-dihydroquinoline. N-Ethylbenzisoxazolium fluoroborate. Ethyl chloroformate. N-Ethyl-5-phenylisoxazolium-3 -sulfonate. N-Hydroxysuccinimide trifluoroacetate. Methyl-morpholine. 4-Methylthiophenol. p-Nitrophenol. Oxalylchloride. Pentachlorophenol. Pentamethylbenzyl chloride. /-Pentyl chloroformate. Phenacyl bromide. Polyhexamethylene carbodiimide. Tetraethyl pyrophosphite. 1,2,4-Triazole. 

Euphococcinine and adaline (333) were synthesized from a 2-cyano-6-oxazolopiperidine [699], An anion at C(2) was condensed with 3-bromo-2-methoxy-l-propene, and after elimination of cyanide, the resultant iminium ion was alkylated with either a methyl- or pentyl-Grignard reagent to form the quaternary carbon. The second ring was closed with an intramolecular Mannich reaction. 

A mixture of ice (500 g) and concentrated sulfuric acid (500 g) is cooled to 0° and 2-methyl-2-butene (500 ml) is added to it with vigorous stirring. The mixture is stirred for a further hour, then the aqueous layer is separated from the unchanged olefin, poured on ice(ca. 2 kg), neutralized cautiously with a concentrated solution of sodium hydroxide (720 g), and distilled until addition of potassium carbonate to a portion of the distillate no longer separates pentyl alcohol. Addition of potassium carbonate to the distillate causes separation of the tert-pentyl alcohol, which is dried with the same reagent and distilled, affording ca. 90% of the pure alcohol, b.p. 103°. 

Hydroxy-6-methyl-2-pentyl-9-oxo-10-oxa-phenanthrene with bromoacetaldehyde diethyl acetal in refluxing dimethylformamide containing potassium carbonate, after 30 minutes gave the corresponding acetal in 90% yield which by way of the aldehyde obtained upon acidic hydrolysis with 2M hydrochloric acid in 89% yield furnished with ethanolic 0.1M sodium hydroxide during 30 minutes the benzofuran shown in 91% yield (ref.137) a cyclisation attributable to the highly reactive... 

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