Acetylacetates

A 3,4,8,9-tetrahydropyrido[2,l-c][l,4]thiazine 336 and a benzo(A)-l,4-thiazine 335 was isolated from the reaction mixture of enaminone 334 and 2-(3-chlorobenzylidene)acetylacetate (99T7915). Reactions of enamines 334 and 337 with DMAD in MeOH yielded addition products 338 and 339 and bi- and tricyclic derivatives 340 and 341, respectively. The latters could be obtained in quantitative yields when the addition products 338 and 339 were heated in refluxing MeOH. 

The 3-arylglutaric esters 3 required as substrates were obtained by condensation of 2 equiv. of ethyl acetylacetate with respective benzaldehydes, followed by hydrolysis and decarboxylation of the resulting product under basic conditions. After esterification, ester 3 was obtained in 75% overall yield (R = Cl, = Me) [10]. 

Methoxyethanol 2-Methoxyethyl acetate Methyl acetate Methyl acetoacetate Methyl acetylacetate Methyl acrylate Methylamine 2-Methylbutane 2-Methyl- 1-butanol... 

Bismuth complexes involving ketoalkoxide ligands are rare and are represented by comprehensively characterized examples of an ethyl-maltolatfi Bi(emal)3 (173), a tris(acetylacetonate) (174), an acetylacet-onate Bi(p,-OiPrXO Pr)(i/-acac) (175), and series of tropolonate deriva-... 

The steady-state free-procession (SSFP) technique was used with no NOE, and in the case of aniline the T of the 15N was reduced by addition of chromium acetylacetate as a relaxation reagent to the sample. The 15N spectrum of aniline showed a single broad line (Avi/2 = 42 Hz) in which, because of proton exchange125,126, there is no evidence of N H coupling (J = 80 Hz). 

Catalytic results reported in Table 13.3 show a comparison between a colloidal catalyst and a more conventional preparation procedure using palladium acetylacet-onate as a precursor. These two catalysts have nearly the same dispersion, but the colloidal-based catalyst is roughly six times more active for PhAc hydrogenation. 

Electrochemical oxidations of anions lead to radicals that may add to the carbon-carbon double bonds. In this way, the oxidation of anions of dimethyl malonate or methyl acetylacetate in the presence of olefines gives di- or tetrahy-drofurans derivatives in moderate yields (Scheme 43) [60]. 

A cation arriving with a nncleophilic anion is another important factor. The nucleophile can attack the substrate in the form of a free ion or an ionic pair. As a rule, lithium salts are less reactive than sodium and potassium salts. Russell and Mndryk (1982) reported several examples of this. The sodium salt of ethyl acetylacetate reacts with 2-nitro-2-chloropropane in DMF yielding ethyl 2-(wo-propylidene) acetylacetate. Under the same conditions, the lithium salt does not react at all. Potassium diethyl phosphite interacts with l-methyl-l-nitro-l-(4-toluylsulfonyl)propane in THF and gives diethyl 1-methyl-l-nitro-l-phosphite. The lithinm salt of the same reactant does not react with the same substrate in the same solvent. 

Keywords Acetylacetates, 2-Amino-2-deoxyaldoses, Barbituric acids, C-Glyco-sides, Dimedone, Furans, Garcia-Gonzalez reaction, Green chemistry, Hexoses, Meldrum s acid, Penta-2,4-dione, Pentoses, Pyrroles, Reactions in water, Tetrahy-drofuranylfurans... 

The telomerization of dienes in a two-phase system was first described in a patent (100). Water was used as the solvent for the catalyst, with sulfonated phosphane ligands providing the water solubility. Water, alcohols, phenols, acids, amines, and acetylacetic add were used as nucleophiles. 

Rhone-Poulenc uses carbon-carbon coupling for an efficient route to geranylacetone with a water-soluble Rh/tppts catalyst (141). The addition of myrcene to acetylacetic add methyl ester is regioselective (>99%) [Eq. (15)]. 

Vanadium Bis Cyclopentadionyl Acetylacetic-acid Ethyl Ester Perchlorate. 

Groups probably still active in research on hydrocarbons on metals. (acac) = acetylacetate. VEELS. 

This value of 07 for acetyl is essentially confirmed by other reactivity-based methods. In 1956 Taft28 gave a value of 0.60 for the 0 constant of CH3COCH2, which was based on his analysis of ester reactivity. When the factor of 0.45 is applied, 0/ for acetyl comes out at 0.27 (Section n.B). In 1964 Charton82 derived a value of 0.29, based on a pKa value of 3.58 for acetylacetic acid (water, 25 °C). Substitution of this pKa value into Charton s later regression equation for substituted acetic acids80 gives 0.299 for the 0/ value of acetyl. 

More interestingly, as an oxidative condition with Mn(OAc)3, various macrolide compounds (230) are obtained in high yields by the treatment of bis(acetylacetate) (228) and bis(olefin) (229) with Mn(OAc)3 in acetic acid under highly diluted conditions (2 mM of substrate) [237,238]. This reaction proceeds as follows. The initial formation of a (3-keto ester radical via single electron oxidation by Mn(OAc)3 and its addition to olefin occur the formed benzylic radical is oxidized by Mn(OAc)3 to form a benzylic cation, then cyclization by oxygen of the enol form of the (3-keto ester occurs, and again this reaction sequence is repeated in another (3-keto ester group to ultimately form the macrolide compounds. 

The dimerization of ketene leads to the formation of a lactone ( diketene ), the dimerization of dimethylketene furnishes a cyclobutanedione. In Figure 6.25, diketenes were introduced as reagents acylating alcohols to acetylacetates. 

Commercial l-chloro-2,4-dinitrobenzene prepared by the nitration of a mixture of o- and p- chloronitrobenzenes usually contains the 1,2,6-isomer. The latter differs from the 1,2,4-isomer in some of its properties. According to Borsche and Rants-cheff [24], only the 1,2,4-isomer can react with the sodium salt of acetylacetic ester, the 1,2,6-isomer remaining unchanged. 

Boit (97) and Leete (98) suggested that in the biogenesis of pilocarpine, the imidazole compound 47 reacts with acetylacetic acid (48). It should be remarked that the phosphate of 47 is assumed to be an intermediate in the biogenesis of histidine. The reaction between the methylene group in 48 and... 

In the transfer hydrogenation of acetylacetates ephedrinium chelates of ruthenium led to 94 % ee [65]. 

Step 3 dithieno[2,3-b 3, 2 -l]thiophene derivatives, (I), have also been prepared by oxidative coupling using iron(III)acetylacetate (2) as illustrated in Eq. 1 and described (2). 

It was a particular interest for us to study the preparation of P,p-carboranyl derivatives, which are synthons for a number of compounds. We found that interaction of compound 16 with the magnesium enolate of acetylacetic ester in Et20/EtOH results in esterification of 16 by the EtOH solvent. The same reaction with the sodium enolate of acetylacetonate results in the product of O-acylation. We also found a general method of preparation of carboranyl p,p-diketones (e.g., 19) by reaction of 16 with enamines (Scheme 8). 

METHYL ACETYLACETATE see MFX250 METHYL ACETYLACETONATE see MFX250... 

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