Butene-2-carboxylic acid

B 177 m-2-Butene, copolymer (alt) with ethylene B 178 l-Butene-2-carboxylic acid. See Acrylic acid, 2-ethyl-. B 179 ra i -Butenedioic acid. See Fumaiic acid. 

Butadiene-1,3 (Pd(P(C6H5)3)2Cl2/HCl Butene-2-carboxylic acid-1 70 [469]... 

This reagent combination also converts carboxylic acids to acyl chlorides (see Section 3.4.1). The mechanistic basis for the special effectiveness of benzotriazole has not yet been determined, but it seems likely that nucleophilic catalysis is involved. Sulfinyl ester intermediates may be involved, because Z-2-butene-l,4-diol gives a cyclic sulfite ester with one equivalent of reagent but the dichloride with two equivalents. 

Buten-4-carboxylic acid, p51 cw-2-Butenedioic acid, ml 2-Butene-l,l-diol diacetate, d28 ra s,-2-Buten-l-ol, c311... 

The preparation described here of 3-cyclopentene-1-carboxylic acid from dimethyl malonate and cis-1,4-dichloro-2-butene is an optimized version of a method reported earlier3 for obtaining this often used and versatile building block.6 The procedure is simple and efficient and requires only standard laboratory equipment. 3-Cyclopentene-1-carboxylic acid has previously been prepared through reaction of diethyl malonate with cis-1,4-dichloro(or dibromo)-2-butene in the presence of ethanolic sodium ethoxide, followed by hydrolysis of the isolated diethyl 3-cyclopentene-1,1-dicarboxylate intermediate, fractional recrystallization of the resultant diacid to remove the unwanted vinylcyclopropyl isomer, and finally decarboxylation.2>7 Alternatively, this compound can be obtained from the vinylcyclopropyl isomer (prepared from diethyl malonate and trans-1,4-dichloro-2-butene)8 or from cyclopentadiene9 or cyclopentene.10 In comparison with the present procedure, however, all these methods suffer from poor selectivity, low yields, length, or need of special equipment or reagents, if not a combination of these drawbacks. 

Volume 75 concludes with six procedures for the preparation of valuable building blocks. The first, 6,7-DIHYDROCYCLOPENTA-l,3-DIOXIN-5(4H)-ONE, serves as an effective /3-keto vinyl cation equivalent when subjected to reductive and alkylative 1,3-carbonyl transpositions. 3-CYCLOPENTENE-l-CARBOXYLIC ACID, the second procedure in this series, is prepared via the reaction of dimethyl malonate and cis-l,4-dichloro-2-butene, followed by hydrolysis and decarboxylation. The use of tetrahaloarenes as diaryne equivalents for the potential construction of molecular belts, collars, and strips is demonstrated with the preparation of anti- and syn-l,4,5,8-TETRAHYDROANTHRACENE 1,4 5,8-DIEPOXIDES. Also of potential interest to the organic materials community is 8,8-DICYANOHEPTAFULVENE, prepared by the condensation of cycloheptatrienylium tetrafluoroborate with bromomalononitrile. The preparation of 2-PHENYL-l-PYRROLINE, an important heterocycle for the synthesis of a variety of alkaloids and pyrroloisoquinoline antidepressants, illustrates the utility of the inexpensive N-vinylpyrrolidin-2-one as an effective 3-aminopropyl carbanion equivalent. The final preparation in Volume 75, cis-4a(S), 8a(R)-PERHYDRO-6(2H)-ISOQUINOLINONES, il lustrates the conversion of quinine via oxidative degradation to meroquinene esters that are subsequently cyclized to N-acylated cis-perhydroisoquinolones and as such represent attractive building blocks now readily available in the pool of chiral substrates. 

The resulting butene molecule under2 oes selective oxidation where the two terminal metbyl groups are converted to carboxylic acid groups... 

Alkenes are directly oxidized to aldehydes and/or ketones by ozone (O3) at low temperatures (—78 °C) in methylene chloride, followed by the reductive work-up. For example, 2-methyl-2-butene reacts with O3, followed by a reductive work-up to yield acetone and acetaldehyde. This reducing agent prevents aldehyde from oxidation to carboxylic acid. 

Ionic copolymers are composed from an a-olefin with an olefin content of 80 mol-% and an ethylenically unsaturated carboxylic acid (6). Suitable olefins include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, etc. 

Resin-bound (4-acyloxy-2-buten-l-yl)silanes, which can be prepared from resin-bound allylsilanes and allyl esters by cross-metathesis, react with dilute TFA to yield free carboxylic acids (Figure 3.7 [75]). However, the scope of this strategy remains to be explored. Similarly, esters of polystyrene-bound (2-hydroxyethyl)silanes readily undergo acidolysis and have been used as acid-labile linkers (Figure 3.7 [76]). 

Figure 3.7. (4-Acyloxy-2-buten-l-yl)silanes and 2-acyloxyethylsilanes as acid-labile linkers for carboxylic acids.

The synthesis of 207 is based on an intramolecular aminolysis of the (3-lactam ring in 206. This latter compound was prepared by stereoselective alkylation of 203 with l-bromo-3-butene and subsequent oxidative cleavage of the double bond to give the carboxylic acid 204, which next was coupled with 205. The resulting peptide product 206 rapidly cyclized to a ten-membered ring compound, on reductive deprotection of the hydrazine group, and then coupled with /V-carbo-benzoxytyrosine to give 207. 

Butenal, c282 Buten-4-carboxylic acid, p50 Butopyronoxyl, b445... 

Methyl bromide, b300 3-Methyl-1-buten-l-carboxylic acid, m349... 

On the other hand, when propargyl alcohols are treated with the same catalyst precursor [Cp RuCl(COD)j in the presence of a carboxylic acid, the catalytic reaction takes a different route, leading to the selective formation of alkenylidenecydo-butenes (Scheme 5) [24, 25]. 

Scheme 7. Catalytic cycle for formation of alkenylidenecyclo-butenes from alkynols and carboxylic acid.

For the manufacture of non-crosslinked ionomer polymer mixtures ethylene, butene-1, isobutylene, vinyl chloride, vinylidene chloride, aliphatic carboxylic acids of vinyl esters (C2-C18), aliphatic unsaturated mono and di carboxylic organic acid esters (C3-C8) with mono aliphatic saturated alcohols (C2-C12) and unsaturated aliphatic mono and di carboxylic organic acids (C3-C8) can be used as raw materials. 

A complex network of reactions is hidden behind the simple stoichiometry of -butane oxidation (Equation 35). Butene, butadiene and furan have been suggested to be intermediates in a cascade of reactions eventually producing the anhydride. Carboxylic acids and carbon oxides are formed in parallel and consecutive oxidations. 

Carboxylic acids Phenacyl bromide. 2-Pyri-dimethanol. 4-Trimethylsilyl-2-butene-1 -ol. 

Hydroboration. Thexylborane stabilized as the triethylamine complex is not useful for hydroboration, because 2,3-dimethyl-2-butene is displaced with formation of RBH2-N( 2145)3. However, TBDA is a useful reagent for hydroboration and for various reductions. Thus it reacts with 1-octene to form di- -octylthexylborane in quantitative yield. It is comparable to thexylborane-THF for reduction of aldehydes and ketones. Carboxylic acids are reduced to the corresponding alcohol. 10-Undecenoic acid is reduced selectively to undecanoic acid (90% yield). Tertiary amides are reduced very rapidly to f-amines. Acid chlorides and nitriles are reduced very slowly. 

R and R may be H, methyl, cyclopropyl, cyano, or ester groups. The phenylcarbene formed on irradiation of trans-l,2-diphenyloxirane has been trapped and identified in the form of a cyclopropane derivative in methanol in the presence of benzyl methyl ether and alkenes. Photolysis in the presence of 2,3-dimethyl-2-butene proceeds by cycloaddition with the formation of cyclopropane-carboxylic acid and oxetane derivatives (Eq. 368). ... 

Biochemical reactions of l-amino-2-ethylcyclopropane-l-carboxylic acid showed strong stereoselectivity. Thus, ring-opening to 2-ketohexanoate was observed only with the (IS, 2S)-isomer (505) . On the other hand, cycloelimination to give butene by the ethylene forming enzyme in apples or pea epicotyls was performed preferentially with allocoronamic acid (649), the (IR, 2S)-isomer Pea epicotyl enzyme (cell-free system) catalyzed the formation of 1-butene for all stereoisomers (i.e. 505 and 649)" ... 

A further oxidation is then performed to establish the carboxylic acid moiety at C-1, which will form the macrolactone later in the synthesis. Sodium chlorite is commonly used as an oxidizing agent and is often applied for saturated and aromatic aldehydes. Hypochloric acid (HOCl) and sodium hypochlorite (NaOCl) are formed as byproducts and have to be destroyed before they can attack the substrate or the product, because they are stronger oxidizing agents. In this case, 2-methyl-2-butene (43) is added to the reaction mixture forming a chlorohydrin 44. 

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 action of a Zn/Cu couple on 1,3-dibromo ketones and secondary amides yields 2-dialkylamino-1,3-dioxolanes (451 equation 208). Fluorosulfonic peracid anhydride adds to trifluoroacetonitrile to give an amide acetal (452 equation 209). In the addition of (Z)-2-butene-l,4-diol to trichloroacetoni-trile, catalyzed by sodium, the 1,3-dioxepin (453 equation 210) is produced. Bicyclic amide acetals (454 equation 211) are byproducts in the reaction of lactim ethers with diketene. TTie methyl esters of perfluorinated carboxylic acids react with diethanolamine to afford bicyclic amide acetals (455 equation 212). Heating of maleic anilides (456 equation 213) with acetic acid anhydride/sodium acetate gives heterocyclic compounds (457) containing an amide acetal structure. ... 

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