Ethyl 4 -carboxylates

Hydrogenolysis of the diallyl alkylmalonate 757 with formic acid in boiling dioxane affords the monocarboxylic acid 758. Allyl ethyl malonates are converted into ethyl carboxylates[471]. The malonic allyl ester TV-allylimide 759 undergoes smooth deallylation in refluxing dioxane to give the simple imide 760(472]. The allyl cyanoacetate 761 undergoes smooth decarboxylation to give... 

Regioselective Acylation of Hydroxy Compounds. AUphatic diols can be selectively acylated at the primary position by a number of Upases in nonaqueous solvents. For example, PPL suspended in solutions of various diols in ethyl carboxylates catalyzes transesterification in a highly regioselective manner, producing primary monoesters in up to 97% yield (93). Similarly, chloramphenicol [56-75-7] (72) (R = NO2) can be acylated by a number of Upases to produce optically pure, water-insoluble 3-0-palmitate in a highly selective manner (94). 

A second patent application appeared in 2005, in which a series of pyrrolo[l,2-b]pyridazine-5,6-dicarboxylates was disclosed [31]. Several of the described compounds (exemplified by structure 8) were reported to have IC50 values of < 0.5 iM against DGAT-1. Various hydrophobic and amino substitutions at positions 4 and 7, and 2, respectively, were tolerated on the heterocyclic ring, along with heterocyclic replacements for the 6-substituted ethyl carboxylate. 

The effect of carboxylate and/or sulfonate ion incorporation on the physical and blood contacting properties of polyurethanes was studied by Cooper and collaborators [476-478]. Specifically, propyl sulfonate and ethyl carboxylate groups were grafted onto polytetramethylene oxide-based polyurethanes. Carboxylate polymers had no statistically significant effect on canine ex vivo blood contact response, but propyl sulfonate incorporation significantly reduced platelet deposition for very short blood contact times. 

Fig. 4. Log rates of basic hydrolysis of 5-X-thiophene-2-ethyl carboxylates vs. ap (see Table VIII).

Fig.6.3.3. Typical chromatograms of products (analyzed as ethylated carboxylic acid methyl esters) obtained in the permanganate oxidation of spruce (a) and birch (b) wood (Numbered peaks refer to structures listed in Fig 6 3 2)...

Triazonane bearing three ethyl carboxylate 2,2 -bipyridine units was synthesized in 83% yield from the corresponding 6-bromo derivative 200 by a carboalkoxylation reaction promoted by a catalytic amount of Pd(0) (Equation 13). Subsequent smooth saponification resulted in the tris-acid 201 in 80% yield <2001JA2436, 2002JOC3933>. 

Ozonolysis of tosyl derivative 295a led to the corresponding protected azonane-3,8-dione in 50% yield (Equation 41). Ruthenium-catalyzed oxidation was found to be more efficient, resulting in an increased 70% yield of the product, which is consistent with the result obtained for dialkyl-substituted systems (Scheme 32, Section 14.10.6.3) <1995J(P1)1137>. Similar ozonolysis of pyrrolo ethyl carboxylate 295c led to 75% of cyclic amino acid derivative <20010L861>. 

Oxo-substituted ethyl carboxylates 2 yield the corresponding 3,3-difluorocarboxylatcs 3 in good yields. ... 

Sutherland and coworkers used ethyl carboxylate protecting groups when they reacted an oligo(ethyleneoxy)bis(carbamate) with a ditosylate or dihalide... 

The phenylsulfinyl fluoroacetate can be alkylated with a wide range of alkyl halides and Michael acceptors. Subsequent thermal elimination of phenyl sulfinic acid leads to a-fluoro-a,p-unsaturated ethyl carboxylates, an important class of intermediates for fluorine containing biologically active compounds [19] (Scheme 5.4). 

Methylselenol esters. Methyl and ethyl carboxylic esters are converted into methylselenol esters by this reagent (0°-20°). 

Kinetic resolution was shown by Kunieda and coworker to be another enantioselective process of a-sulfinyl carbanions. Slight asymmetric induction was achieved in the reaction of racemic a-lithiomethyl p-tolyl sulfoxide with ethyl carboxylates in the presence of (-)-sparteine [Eq. (17)] [62]. 

Concerning the first approach, methyl or alkyl protection of the phosphinic group requires suitable masking of the carboxylic terminus of the main pseudodi-peptidic unit which could be selectively removed prior to C-elongation. Selective deprotection of carboxylic esters in the presence of alkyl phosphinates include enzymatic hydrolysis of methyl carboxylates [18, 58], controlled alkaline hydrolysis of ethyl carboxylates [59, 60], acidic cleavage of 3,4-dimethoxybenzyl... 

Synonyms Butanoic acid, 2-ethyl- Carboxylic acid C-6 2-Ethyl butanoic acid Ethylbutyric acid 2-Ethyl butyric acid a-Ethylbutyric acid 3-Pentanecarboxylic acid... 

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