Butadiene-l-carboxylic acid

Asymmetric induction to main-chain chiral centers can also be achieved by the radical polymerization of sorbates having chiral ester groups [80,81] and 1,3-butadiene-l-carboxylic acid complexed with optically active amines [82,83]. 

Palladous acetate and trimethyl phosphite added to a soln. of 4-vinyl-2-oxetanone in methylene chloride, and stirred 0.5 hr. at room temp, under N2 -> (E)-l,3-butadiene-l-carboxylic acid. Y 80-90%. F. e. and products s. A. F. Noels, J. J. Herman, and P. Teyssie, J. Org. Chem. 41, 2527 (1976). 

Dihydrothiophene 1,1-dioxide in the presence of l,8-diazabicyclo[5.4.0]undec-7-ene (DBU) reacts with CO2 to give the carboxylic acid (Equation 69), which is a stable precursor to l,3-butadiene-2-carboxylic acid <2003SC3643>. The reaction proceeds through initial deprotonation at the 2a-position the resonance-stabilized carbanion thus generated reacts with CO2 to form the carboxylate. Abstraction of a proton from the 3-position by another molecule of the base generates a dianion, which isomerizes to the stable dianion as shown in Scheme 39. Final protonation produces 3-sulfolene-3-carboxylic acid. 

An "updated" version of this sequence is the reaction of the butadiene surrogate 3-sulfolene with maleic anhydride to give 7.175. Subsequent hydrogenation of the double bond gave anhydride 7.181, and this was then treated with trimethylsilyl azide to give ds-2-aminocyclohexane-l-carboxylic acid, 7.777.HI The transformation of 7.187 to 7.777 probably proceeds via a transient isocyanate, 7.183. Formation of an isocyanate such as this and its conversion to the amino acid 7.183 to 7.777) had been reported in earlier work. S... 

The enantioselective intramolecular formal 2+4-cycloaddition of acrylates and a, -unsaturated imines (99) catalysed by chiral phosphines (100), derived from amino acids, produced A-heterocycles (101) (Scheme 31). Chiral dirhodium(II) carboxamidates (102) catalysed the hetero-Diels-Alder reactions between 2-aza-3-silyloxy-l,3-butadienes and aldehydes to yield all cw-substituted l,3-oxazinan-4-ones in high yields and high enantioselectivity (98% ee)P The nickel-catalysed 4 + 2-cycloaddition of a, -unsaturated oximes with alkynes yielded 2,3,4,6-tetrasubstituted pyridine derivatives. The reaction of isoquinoline, an activated alkyne, and 4-oxo-4//-l-benzopyran-3-carboxaldehyde (103), in ionic solvents, produced 9a//,15//-benzo[a][l]benzopyrano[2,3-/t]quinolizine derivatives (105) via the zwitterion (104) selectively and in good yields (Scheme 32).The Diels-Alder cycloaddition of ethyl 3-(tetrazol-5-yl)-l,2-diaza-l,3-butadiene-l-carboxylates with -rich heterocycles, nucleophilic olefins, and cumulenes formed 3-tetrazolyl-l,4,5,6-tetrahydropyridazines regioselectively. The silver-catalysed formal inverse-electron-demand Diels-Alder... 

Carboxylic acids react with butadiene as alkali metal carboxylates. A mixture of isomeric 1- and 3-acetoxyoctadienes (39 and 40) is formed by the reaction of acetic acid[13]. The reaction is very slow in acetic acid alone. It is accelerated by forming acetate by the addition of a base[40]. Addition of an equal amount of triethylamine achieved complete conversion at 80 C after 2 h. AcONa or AcOK also can be used as a base. Trimethylolpropane phosphite (TMPP) completely eliminates the formation of 1,3,7-octatriene, and the acetoxyocta-dienes 39 and 40 are obtained in 81% and 9% yields by using N.N.N M -tetramethyl-l,3-diaminobutane at 50 in a 2 h reaction. These two isomers undergo Pd-catalyzed allylic rearrangement with each other. 

Carboxylic acids, a-bromination of 55, 31 CARBOXYLIC ACID CHLORIDES, ketones from, 55, 122 CARBYLAMINE REACTION, 55, 96 Ceric ammonium nitrate [Ammonium hexa mtrocerate(IV)[, 55, 43 Chlorine, 55, 33, 35, 63 CHROMIUM TRIOXIDE-PYRIDINE COMPLEX, preparation in situ, 55, 84 Cinnamomtnle, a-phenyl- [2-Propeneni-tnle 2,3-diphenyl-], 55, 92 Copper(l) iodide, 55, 105, 123, 124 Copper thiophenoxide [Benzenethiol, copper(I) salt], 55, 123 CYCLIZATION, free radical, 55, 57 CYCLOBUTADIENE, 55, 43 Cyclobutadieneiron tricarbonyl [Iron, tn-carbonyl(r)4-l,3-cyclo-butadiene)-], 55,43... 

Isomerization has been observed with many a,j3-unsaturated carboxylic acids such as w-cinnamic 10), angelic, maleic, and itaconic acids (94). The possibility of catalyzing the interconversion of, for example, 2-ethyl-butadiene and 3-methylpenta-l,3-diene has not apparently been explored. The cobalt cyanide hydride will also catalyze the isomerization of epoxides to ketones (even terminal epoxides give ketones, not aldehydes) as well as their reduction to alcohols. Since the yield of ketone increases with pH, it was suggested that reduction involved reaction with the hydride [Co" (CN)jH] and isomerization reaction with [Co (CN)j] 103). A related reaction is the decomposition of 2-bromoethanol to acetaldehyde... 

The photolysis of the furan derivatives 78 yielded the butadienals 79 as the main products [123], Further isomerizations leading to allenic esters used the radiation of a cyclopropene-1 -carboxylic acid ester [124] or applied flash vacuum pyrolysis to 3 -ethoxy cyclobut- 2-en-l-one[125]. 

Several polymers based on 1,3-dienes are used as elastomers. These include styrene-1,3-butadiene (SBR), styrene-1,3-butadiene terpolymer with an unsaturated carboxylic acid (carboxylated SBR), acrylonitrile-1,3-butadiene (NBR or nitrile rubber) (Secs. 6-8a, 6-8e), isobutylene-isoprene (butyl rubber) (Sec. 5-2i-l), and block copolymers of isoprene or... 

The 3-alkyl-l,3-butadiene-2-carboxylate (2-vinylacrylate) 850 is obtained in a high yield by the carbonylation of the 2-alkyl-2,3-butadienyl carbonate 849 under mild conditions (room temperature, 1 atm)[522]. The corresponding acids are obtained in moderate yields by the carbonylation of 2,3-alkadienyl alcohols under severe conditions (100°C, 20 atm) using a cationic Pd catalyst and p-TsOH[523],... 

Mechanistic studies of the pyrolysis of disodium peifluoropentanedioate and derivatives have shown that the acid fluorides are formed during the reaction. The formation of dienes from the salts of halogcnalcd carboxylic acids with a terminal C = C bond is also possible. The thermal decomposition of sodium (Z)-6//-perfluoro 6-chlorohex-5-cnoate) gives (Z)-l//-perfluoro(l-chloropenta-l,4-diene) (7) in 75% yield.The decarboxylation of potassium 5H-pcrfluoropcnt-4-enoate, however, gives 1//-perfluorobut-2-yne (8) via the isomerization of the intermediate butadiene by potassium fluoride. ... 

---