Trans-1,2-dicarboxylate

Irradiation of the sodium salt 517 in a solution of maleonitrile in THF gave a 30% yield of the as-spiro[2.6]nonatrienedicarbonitrile 524 (Scheme 6.106). Analogously, fumaronitrile led to the trans-diastereomer 525 exclusively in 29% yield [193b], which was also obtained from (trimethylsilyl)tropylium tetrafluoroborate (519) as precursor of 5 [208]. The interception of 5 by dimethyl fumarate succeeded by generating 5 from 517 by either photolysis [193] or thermolysis [193, 194] and from 519 [208] and afforded the dimethyl trans-dicarboxylate 526 in yields of 50, 40 and 42%, respectively. Liberation of 5 in the presence of dimethyl maleate led also to 526 [194, 214], In this reaction, the isomerization of dimethyl maleate to fumarate could have interfered and hence pretended the loss of the stereochemical information, since... 

The trans-dicarboxylic acid cannot form the anhydride because a five- and a four-membered ring cannot be fused tram. 

NMR spectrum allow you to prove that the cis- rather than the trans-dicarboxylic acid was produced by the hydrolysis of anhydride 6 Explain. 

Gycloalkane-l,2-dicarboxylic acids via cycloalkane-1,1,2,2-tetracarboxylic acid esters CIS- from trans-Dicarboxylic acids via cis-dicarboxylic acid anhydrides... 

C10H12O2, 4-Isopropyltropolone, 38B, 187 CioHisOft, Cyclooctane-cis-1,2-dicarboxylic acid, 33B, 85 CioHicOn, Cyclooctane-1,2-trans-dicarboxylic acid, 31B, 92 ClaBrOs, 4-Bromo-2,3-dicarbomethoxy-2-cyclohepten-1-one, 40B, 148 CliHiftOs, 1-Hydroxy-2,3-dicarbomethoxy-l,3-cycloheptadiene, 42B, 113 Cl2CI14, Perchloro-4,7-dimethyl-3,8-dimethylene-cyclo-octa-1,4,6-triene, 33B, 86... 

Fumaric acid must be the trans-dicarboxylic acid ... 

Being a trans dicarboxylic acid, fumaric acid must undergo isomerization to maleic acid first. This isomerization requires a higher temperature. 

Cyclohexanedimethanol (47) starts from dimethyl terephthalate. The aromatic ring is hydrogenated in methanol to dimethyl cyclohexane-l,4-dicarboxylate (hexahydro-DMT) and the ester groups are further reduced under high pressure to the bis primary alcohol, usually as a 68/32 mixture of trans and cis forms. The mixed diol is a sticky low melting soHd, mp 45—50°C. It is of interest that waste PET polymer maybe direcdy hydrogenated in methanol to cyclohexanedimethanol (48). 

Butene-l,4-dicarboxylic acid (trans-3-hexenedioic acid, traits-8-hydromuconic acid) [4436-... 

Maleic acid and fumaric acid are the cis- and trans- isomers, respectively, of QH COOH) a dicarboxylic acid. Draw and label their structures. 

Iodine azide, generated in situ from an excess of sodium azide and iodine monochloride in acetonitrile, adds to ethyl l//-azepine-l-carboxylate at the C4 — C5 and C2 —C3 positions to yield a 10 1 mixture of the rw-diazidodihydro-l//-azepines 1 and 2, respectively.278 The as stereochemistry of the products is thought to be the result of initial trans addition of the iodine azide followed by an SN2 azido-deiodination. The diazides were isolated and their stereochemistry determined by conversion to their bis-l,3-dipolar cycloadducts with dimethyl acetylene-dicarboxylate. 

With cyanide ion in aqueous ethanol azepinedicarboxylate 3 forms the corresponding racemic 4,5-dihydro-l//-azepine-4-carbonitrile (85%),121,241 whereas with dimethyl 2,5,7-trimethyl-4//-azepinc-3,6-dicarboxylate (6) diastereospecific addition occurs to give racemic lrans-5-me thy 1-4.5-di hydro-1-//-azepine-4-carbonitrile 7 together with a small amount of the trans 4S-methoxy-5 / -methyl compound 8.121... 

For example. 2-ethoxyindole (1 a) with the alkyne diester in refluxing dioxane yields dimethyl 2-ethoxy-3//-l-benzazepine-3,4-dicarboxylate (2) as a minor product along with a 50 % yield of a mixture of the cis- and tran.v-indol-3-ylacrylates 3.20 However, with 2-ethoxy-l-methylindole (1 b) the l//-l-benzazepine 4 becomes the major product. An analogous reaction with l,2-bis(trifluoromethyl)acetylene to yield 2-ethoxy-l -methyl-3,4-bis(trifluoroiriethyl)-1 //-1-benzazepine has been performed however, the yield was not reported.142... 

Chrysanthemum dicarboxylic acid or pyrethric acid may exist in eight stereoisomers, owing to the trans or cis configuration on the side chain of the double bond as well as that of the cyclopropane. The natural acid has been shown to be the trans-trans acid. As in the case of the chrysanthemum monocarboxylic acid, the naturally occurring configuration is more insecticidally active than the racemic form or any of the three isomers synthesized. 

As the mechanism, a radical and a cationic pathway are conceivable (Eq. 31). The stereochemical results with rac- or mcjo-1,2-diphenyl succinic acid, both yield only trans-stilbene [321], and the formation of a tricyclic lactone 51 in the decarboxylation of norbornene dicarboxylic acid 50 (Eq. 32) [309] support a cation (path b, Eq. 31) rather than a biradical as intermediate (path a). 

Dialkyl esters of cystine (39) and lanthionine (40) undergo a surprising thermolysis reaction at between 25 C and 80 °C to afford cis and trans methyl 2-methylthiazolidine-2,4-dicarboxylates (43) in protic solvents. A two stage process is proposed for this transformation. An initial i-elimination reaction gives the thiol (41) and the enamine (42). Thiol addition to the imine tautomer of (42) is then followed by loss of ammonia and an intramolecular cyclisation to give (43) <96CC843>. 

Figure 4.5 A MOF oxidation catalyst based on Cu paddlewheels connected by 1,4-trans-cyclohexane-dicarboxylate ligands (only carboxylate groups are explicitly shown). After oxidation by H2O2, paddlewheels are linked by peroxo bridges (Cu = blue O = red C = gray) [34], (Reproduced by permission of the Royal Society of Chemistry.)...

Energy is transferred from molecules electronically excited in a chemical reaction to other molecules which emit the accepted excitation energy in the form of light alternatively the accepting molecules can undergo photochemical transformations. First examples of this photochemistry without light were described by E. H. White and coworkers 182>. Thus the trans-stilbene hydrazide 127, on oxidation, yielded small amounts of the cis- 128 beside the trans-stilbene dicarboxylate in a luminol-type reaction. 

FIGURE 1.15 Isomers of cyclopropane-l,2-dicarboxylic acid, (a) Trans isomer (b) meso isomer. 

A related geometry results from the use217 of 2,6-pyridine dicarboxylate in Ph2SnC7H3N04-H20. The two phenyl groups are at normal distances and trans (CSnC = 172°). The tridentate ligand occupies three sites in the equatorial plane and the coordinated... 

Diesters and even triesters have been converted to bis- and tris(cyclopropanol)s, respectively. Dimethyl succinate gave the bis (cyclopropanol) derivative 17 in 80% yield, while triethyl trans-cyclopropanetricarboxylate (18) yields the tris (cyclopropanol) 19 (90%) (Scheme 11.4 selected examples in Table 11.2) [77,78], Higher homologous dicarboxylic acid diesters are likewise smoothly converted with ethylmagnesium bromide in the presence of Ti(OiPr)4 to provide the corresponding bis (cyclopropanol) s [71,78]. 

Exudation occurs in response to environmental constraints, especially P deficiency (e.g., Jones 1998 Hinsinger et al. 2003) and differs depending on the P-form (Lambers et al. 2002) and plant species (Nuruzzaman et al. 2006). Banksia grandis exuded citrate, malate, and trans-aconitate when supplied with aluminium-phosphate. It exuded less of these tricarboxylates and dicarboxylates, but instead lactate and acetate, when supplied with iron-phosphate (Lambers et al. 2002). Plant species differ in their abilities to use various P species (van Ray and van Diest 1979), which can be due to differences in their exudation behavior (Nuruzzaman et al. 2006) and acidification of the root zone (Haynes 1992). This can influence the interspecific competition and coexistence of species, as we will discuss later. 

The BASF route started from hydroquinone, which was converted to 2,5-dihydroterephthalic acid by a Kolbe-Schmitt reaction. One mole of this acid was treated with two moles of an arylamine, both components being in the form of a suspension in aqueous methanol. This was added to a small amount of a solution of vanadium(III) chloride and sodium chlorate. Gentle heating gave a 95% yield of 2,5-bis(arylamino)benzo-l,4-quinone-3,6-dicarboxylic acid. Ring closure to the trans-quinacridonequinone took place in the presence of concentrated sulphuric acid at 60-80 °C. This was then reduced to the required crude pigment by zinc or aluminium powder in caustic soda under pressure,in an aluminium chloride/urea melt or by the use of a sulphuric acid/polyphosphoric acid mixture. 

Cyclohexanone, 2-hydroxymethyl-ene-, preparation of, 54, 38 reaction with alkylenedithio-tosylates, 54, 37 Cyclohexanone, 2,2-trimethy1-enedithio-, 54, 39 4-CYCLOHEXENE—1,2-DICARBOXYLIC ACID, DIETHYL ESTER, trans-, 50, 43... 

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