Hexadienic acid

Hexadienoic acid hexadienic acid (2-butenylidene) acetic acid 2-pro-penylacrylic acid Solid White 112.14... 

SYNS (2-BUTENYLIDENE)ACETIC ACID CROTYL-IDENE ACETIC ACID HEXADIENIC ACID HEXADIENOIC ACID 2,4-HEXADIENOIC ACID trans-trans-2,4-HEXADIENOIC ACID 1,3-PENTADIENE-l-CARBOXYUC ACID 2-PROPENYLACRYLIC ACID SORBISTAT... 

E200 (2-butenylidene) acetic acid crotylidene acetic acid hexadienic acid hexadienoic acid 2,4-hexadienoic acid 1,3-pentadiene-l-carboxylic acid 2-propenylacrylic acid ( , )-sorbic acid Sorbistat K. 

Hexadienic acid Hexadienoic acid 2,4-Hexadienoic acid. See Sorbic acid... 

Synonyms (2-Butenylidene) acetic acid Crotylidene acetic acid Hexadienic acid Hexadienoic acid 2,4-Hexadienoic acid 1,3-Pentadiene-1-carboxylic acid 2-Propenylacrylic acid... 

Hexadecylpyridinium chloride 1-Hexadecylpyridinium chloride n-Hexade-cylpyridinium chloride. See Cetylpyridinium chloride Hexadecyl sodium sulfate. See Sodium cetyl sulfate Hexadecyl stearate n-Hexadecyl stearate. See Cetyl stearate Hexadecyl (sulfophenoxy) benzenesulfonic acid, disodium salt See Sodium hexadecyl diphenyl disulfonate Hexadecyl tetradecanoate. See Cetyl myristate Hexadecyltrimethylammonium bromide. See Cetrimonium bromide Hexadecyl trimethyl ammonium chloride. See Cetrimonium chloride Hexadecyl trimethyl ammonium p-toluene sulfonate. See Cetrimonium tosylate Hexadienic acid Hexadienoic acid 2/4-Hexadienoic acid. See Sorbic acid 2/4-Hexadienoic acid potassium salt. See Potassium sorbate Hexaethylene glycol. See PEG-6... 

The l,5-hexadien-3-ol derivatives 792 and 794 are cycli2ed to form the cyclo-pentadiene derivatives 793 and 795 by insertion of an alkene into -allylpalla-dium formed from allylic alcohols in the presence of trifluoroacetic acid (lO mol%) in AcOH[490],... 

The major use of this compound is in the production of mordant and acid dyes. 2-Amino-4-nitropheno1 also has found limited use as an antioxidant and light stabilizer in butyl mbbers and as a catalyst in the manufacture of hexadiene. The compound has been shown to be a skin irritant and continuous exposure should be avoided. Toxicological studies indicate that it is nonaccumulative (162). 

One of the butadiene dimeri2ation products, COD, is commercially manufactured and used as an intermediate in a process called FEAST to produce linear a,C0-dienes (153). COD or cyclooctene [931-87-3], obtained from partial hydrogenation, is metathesi2ed with ethylene to produce 1,5-hexadiene [592-42-7] or 1,9-decadiene [1647-16-1], respectively. Many variations to make other diolefins have been demonstrated. Huls AG also metathesi2ed cyclooctene with itself to produce an elastomer useful in mbber blending (154). The cycHc cis,trans,trans-tn.en.e described above can be hydrogenated and oxidi2ed to manufacture dodecanedioic acid [693-23-2]. The product was used in the past for the production of the specialty nylon-6,12, Qiana (155,156). 

AEyl chloride reacts with sodamide in Hquid ammonia to produce benzene when sodamide is in excess, hexadiene dimer is the principal product, with some trimer and tetramer (C24, six double bonds). AEylation at carbon atoms alpha to polar groups is used in the preparation of a-aEyl-substituted ketones and nittiles. Preparation of P-diketone derivatives, methionic acid derivatives, and malonic ester, cyanoacetic ester, and P-keto-ester derivatives, etc, involving substitution on an alpha carbon between two polar carbonyl groups, is particularly facEe. 

Phosphorus pentachloride, for conversion of pentaacetylgluconic add to add chloride, 41, 80 for oxidation of cycloheptatriene to tropylium fluoborate, 43, 101 with cyanoacetic acid, 41, 5 Phosphorus tribromide, reaction with 1.5-hexadien-3-ol, 41, 50 Phthalic anhydride, reaction with L-phenylalanine to yield N-phthalyl-L-phenylalanine, 40, 82 Phthalic monoperacid, 42, 77 N-Phthalyl-i.-alanine, 40, 84 N-Phthalyl-/3-alanine, 40, 84 N-Phthalylglycine, 40, 84 N-Phthalyl-l-/5-phenylalanine, 40, 82... 

Hexadiene, 55, 109 Hexanoic acid, 55, 27 Hexanoie acid, 2-bromo-, 55,30... 

Reiner AM, GD Hegeman (1971) Metabolism of benzoic acid by bacteria. Accumulation of (-)-3,5-cyclo-hexadiene-l,2-diol-l-carboxylic acid by a mutant strain of Alcaligenes eutrophus. Biochemistry 10 2530-2536. 

The most studied area in this held is the dehydration of oxolanes to butadiene. This type of dehydration is catalyzed by various acidic heterogeneous catalysts. For example, 2,2,5,5-tetramethyloxolane can be dehydrated on Pt/Al203 to 2,5-dimethyl-2,4-hexadiene in good yield (Scheme 5.3).34... 

For the synthesis of permethric acid esters 16 from l,l-dichloro-4-methyl-l,3-pentadiene and of chrysanthemic acid esters from 2,5-dimethyl-2,4-hexadienes, it seems that the yields are less sensitive to the choice of the catalyst 72 77). It is evident, however, that Rh2(OOCCF3)4 is again less efficient than other rhodium acetates. The influence of the alkyl group of the diazoacetate on the yields is only marginal for the chrysanthemic acid esters, but the yield of permethric acid esters 16 varies in a catalyst-dependent non-predictable way when methyl, ethyl, n-butyl or f-butyl diazoacetate are used77). 

A striking example for the preferred formation of the thermodynamically less stable cyclopropane is furnished by the homoallylie halides 37, which are cyclopro-panated with high c/s-selectivity in the presence of copper chelate 3891 The cyclopropane can easily be converted into cw-permethric acid. In contrast, the direct synthesis of permethric esters by cyclopropanation of l,l-dichloro-4-methyl-l,3-pentadiene using the same catalyst produces the frans-permethric ester (trans-39) preferentially in a similar fashion, mainly trans-chrysanthemic ester (trans-40) was obtained when starting with 2,5-dimethyl-2,4-hexadiene 92). 

The change in selectivity is not credited to the catalyst alone In general, the bulkier the alkyl residue of the diazoacetate is, the more of the m-permethric acid ester results 77). Alternatively, cyclopropanation of 2,5-dimethyl-2,4-hexadiene instead of l,l-dichloro-4-methyl-l,3-pentadiene leads to a preference for the thermodynamically favored trans-chrysanthemic add ester for most eatalyst/alkyl diazoacetate combinations77 . The reasons for these discrepandes are not yet clear, the interplay between steric, electronic and lipophilic factors is considered to determine the stereochemical outcome of an individual reaction77 . This seems to be true also for the cyclopropanation of isoprene with different combinations of alkyl diazoacetates and rhodium catalysts77 . 

The second termination reaction is alkyl chain end transfer from the active species to aluminium [155]. This termination becomes major one at lower temperatures in the catalyst systems activated by MAO. XH and 13CNMR analysis of the polymer obtained by the cyclopolymerization of 1,5-hexadiene, catalyzed by Cp ZrCl2/MAO, afforded signals due to methylenecyclopentane, cyclopentane, and methylcyclopentane end groups upon acidic hydrolysis, indicating that chain transfer occurs both by /Miydrogen elimination and chain transfer to aluminium in the ratio of 2 8, and the latter process is predominant when the polymerization is carried out at — 25°C [156]. The values of rate constants for Cp2ZrCl2/MAO at 70°C are reported to be kp = 168-1670 (Ms) 1, kfr = 0.021 - 0.81 s 1, and kfr = 0.28 s-1 [155]. 

Hydride-promoted reactions are also well known, such as the acrylic and vinylacrylic syntheses (examples 7-10, Table VII). Some less-known compounds, which form in the presence of halide ions added to tetracar-bonylnickel, have been described by Foa and Cassar (example 11, Table VII). Reaction of allene to form methacrylates, and of propargyl chloride to give itaconic acid (via butadienoic acid), have been reported (examples 13 and 14, Table VII). 1,5-Hexadiene has been shown to be a very good substrate to obtain cyclic ketones in the presence of hydrogen chloride and tetracarbonylnickel (example 15, Table VII). The latter has also been used to form esters from olefins (example 16, Table VII). In the presence of an organic acid branched esters form regioselectivity (193). 

R AlB3- (B = OR or NR2). As can be seen from Table XI, the above combination also caused a substantial drop in the catalyst activity, which is expected with a lower overall Lewis acidity of the mixed cocatalyst. The effect of these cocatalysts on the trans/cis ratio of the product is very dependent on the ratios of the two aluminum components. The combination which enables the catalyst system to produce the highest proportion of franj-hexadiene had R2A1B/RA1C12 = 1.5-2 (Table XIII). 

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