Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Amino unsaturated

Similar reactions have been carried out with racemic co-amino- ,/ -unsaturated esters and nitriles34, which are prepared from the corresponding azides, where in situ cyclization affords the pyrrolidines and piperidines in good yield (71 -86%) and diastereoselectivities ranging from 80 20 to 90 10 in most cases. Relative stereochemistry is determined by X-ray structural analysis or analysis of vicinal proton couplings in the H-NMR spectra. [Pg.1103]

The chemical character of the nitro group at various positions in the sugar moiety makes this particular class of functionalized monosaccharides extremely attractive as intermediates for amino, unsaturated, oximino, and deoxy-sugars. [Pg.834]

In confirmation of this expectation, Cromwell et al [6, 35] have found carbonyl shifts of the order of 20—80 cm in /3-amino-unsaturated ketones, although a-amino a/3-unsaturated ketones are normal. They find, however, that there is still a considerable frequency shift in fully substituted amines, although it is not so great as that occurring with materials which can form hydrogen bonds. They conclude that in these substituted amines a resonance is occurring... [Pg.164]

In a similar fashion, olefination of a-amino ketones also induces good Z-selectivity. As shown in Fig. 23, the reaction of the ynolates with the a-amino ketone 71 gives the y-amino unsaturated carboxylates 72, which are treated with mesyl chloride to provide the unsaturated lactams 73 in good yield, without any detection of minor isomers. [Pg.14]

Amino-aromatic carboxylic acids Unsaturated aromatic acid... [Pg.328]

There also exists an acidregioselective condensation of the aldol type, namely the Mannich reaction (B. Reichert, 1959 H. Hellmann, 1960 see also p. 291f.). The condensation of secondary amines with aldehydes yields Immonium salts, which react with ketones to give 3-amino ketones (=Mannich bases). Ketones with two enolizable CHj-groupings may form 1,5-diamino-3-pentanones, but monosubstitution products can always be obtained in high yield. Unsymmetrical ketones react preferentially at the most highly substituted carbon atom. Sterical hindrance can reverse this regioselectivity. Thermal elimination of amines leads to the a,)3-unsaturated ketone. Another efficient pathway to vinyl ketones starts with the addition of terminal alkynes to immonium salts. On mercury(ll) catalyzed hydration the product is converted to the Mannich base (H. Smith, 1964). [Pg.57]

The catalytic oxidative carbonylation of allene with PdCb and CuCh in MeOH affords methyl a-methoxymethacrylate (559)[499]. The intramolecular oxidative aminocarbonylation of the 6-aminoallene 560 affords the unsaturated J-amino ester 561. The reaction has been applied to the enantioselective synthesis of pumiliotoxin (562)[500]. A similar intramolecular oxycarbonyla-tion of 6-hydroxyallenes affords 2-(2-tetrahydrofuranyl)acrylates[501]. [Pg.103]

Other Reactions of Phospholipids. The unsaturated fatty acid groups in soybean lecithin can be halogenated. Acetic anhydride combined with the amino group of phosphatidylethanolamine forms acetylated compounds. PhosphoHpids form addition compounds with salts of heavy metals. Phosphatidylethanolamine and phosphatidjhnositol have affinities for calcium and magnesium ions that are related to interaction with their polar groups. [Pg.99]

Ozonation of Aromatics. Aromatic ring unsaturation is attacked much slower than olefinic double bonds, but behaves as if the double bonds in the classical Kekule stmctures really do exist. Thus, benzene yields three moles of glyoxal, which can be oxidized further to glyoxyUc acid and then to oxahc acid. Substituted aromatics give mixtures of aUphatic acids. Ring substituents such as amino, nitro, and sulfonate are cleaved during ozonation. [Pg.494]

The starting amino acid for nylon-11 is produced from methyl ricinoleate [141 -24-2] which is obtained from castor oil (qv). The methyl ricinoleate is pyrolized to methyl 10-undecylenate [25339-67-7] and heptanal [111-71-7]. The unsaturated ester is hydroly2ed and then converted to the amino acid by hydrobromination, followed by ammoniation and acidification. The CO-amino acid product is a soft paste containing water, which is dried in the first step of the polymeri2ation process. [Pg.236]

These oxazolines have cationic surface-active properties and are emulsifying agents of the water-in-oil type. They ate acid acceptors and, in some cases, corrosion inhibitors (see Corrosion). Reaction to oxazoline also is useful as a tool for determination of double-bond location in fatty acids (2), or for use as a protective group in synthesis (3). The oxazolines from AEPD and TRIS AMINO contain hydroxyl groups that can be esterified easily, giving waxes (qv) with saturated acids and drying oils (qv) with unsaturated acids. [Pg.17]

Also, Michael addition reactions occur between Ai-acylaminomalonic acid esters and unsaturated compounds, ie, acrolein [107-02-8] acrylonitrile [107-13-1y, acryhc acid esters, and amino acids result from hydrolysis of the addition products. [Pg.277]

In an analogous fashion to the hydroboration reaction, a variety of boron-containing substrates react with iminoboranes. Addition of X2B—Cl, X2B—N3, X2B—SR, X2B—NR2, and X2B—R to the unsaturated B—N system is called chloro-, azido-, thio-, amino-, and alkyloboration, respectively. The azidoboration and chloroboration of two iminoboranes are shown ia equations 23 and 24 (72). [Pg.264]

The kinetics of formation and hydrolysis of /-C H OCl have been investigated (262). The chemistry of alkyl hypochlorites, /-C H OCl in particular, has been extensively explored (247). /-Butyl hypochlorite reacts with a variety of olefins via a photoinduced radical chain process to give good yields of aUyflc chlorides (263). Steroid alcohols can be oxidized and chlorinated with /-C H OCl to give good yields of ketosteroids and chlorosteroids (264) (see Steroids). /-Butyl hypochlorite is a more satisfactory reagent than HOCl for /V-chlorination of amines (265). Sulfides are oxidized in excellent yields to sulfoxides without concomitant formation of sulfones (266). 2-Amino-1, 4-quinones are rapidly chlorinated at room temperature chlorination occurs specifically at the position adjacent to the amino group (267). Anhydropenicillin is converted almost quantitatively to its 6-methoxy derivative by /-C H OCl in methanol (268). Reaction of unsaturated hydroperoxides with /-C H OCl provides monocyclic and bicycHc chloroalkyl 1,2-dioxolanes. [Pg.475]

The outstanding chemical property of cyanohydrins is the ready conversion to a-hydroxy acids and derivatives, especially a-amino and a,P-unsaturated acids. Because cyanohydrins are primarily used as chemical intermediates, data on production and prices are not usually pubUshed. The industrial significance of cyanohydrins is waning as more direct and efficient routes to the desired products are developed. Acetone cyanohydrin is the world s most prominent industrial cyanohydrin because it offers the main route to methyl methacrylate manufacture. [Pg.410]

Dyestuff organic chemistry is concerned with designing molecules that can selectively absorb visible electromagnetic radiation and have affinity for the specified fiber, and balancing these requirements to achieve optimum performance. To be colored the dyestuff molecule must contain unsaturated chromophore groups, such as a2o, nitro, nitroso, carbonyl, etc. In addition, the molecule can contain auxochromes, groups that supplement the chromophore. Typical auxochromes are amino, substituted amino, hydroxyl, sulfonic, and carboxyl groups. [Pg.351]

A waterborne system for container coatings was developed based on a graft copolymerization of an advanced epoxy resin and an acryHc (52). The acryhc-vinyl monomers are grafted onto preformed epoxy resins in the presence of a free-radical initiator grafting occurs mainly at the methylene group of the aHphatic backbone on the epoxy resin. The polymeric product is a mixture of methacrylic acid—styrene copolymer, soHd epoxy resin, and graft copolymer of the unsaturated monomers onto the epoxy resin backbone. It is dispersible in water upon neutralization with an amine before cure with an amino—formaldehyde resin. [Pg.370]

Ring fission occurs readily in many of these compounds. For example, azlactones, i.e. 4JT-oxazolin-5-ones containing an exocyclic C=C bond at the 4-position (508), are hydrolyzed to a-benzamido-a,/3-unsaturated acids (509), further hydrolysis of which gives a-keto acids (510). Reduction and subsequent hydrolysis in situ of azlactones is used in the synthesis of a-amino acids e.g. 508 -> 507). [Pg.101]


See other pages where Amino unsaturated is mentioned: [Pg.230]    [Pg.388]    [Pg.230]    [Pg.230]    [Pg.769]    [Pg.426]    [Pg.388]    [Pg.124]    [Pg.230]    [Pg.388]    [Pg.230]    [Pg.230]    [Pg.769]    [Pg.426]    [Pg.388]    [Pg.124]    [Pg.96]    [Pg.95]    [Pg.176]    [Pg.310]    [Pg.308]    [Pg.136]    [Pg.342]    [Pg.295]    [Pg.144]    [Pg.36]    [Pg.427]    [Pg.535]    [Pg.78]    [Pg.265]    [Pg.268]    [Pg.387]    [Pg.171]    [Pg.348]    [Pg.89]    [Pg.115]    [Pg.229]    [Pg.315]    [Pg.136]   


SEARCH



Addition of Amino Acids to Unsaturated Compounds

Amino acids unsaturated

Amino acids unsaturated fluorinated

Amino- -unsaturated ketones

Enantiopure unsaturated amino acids

From Unsaturated Amino Acids

Hydrogenation of unsaturated amino acids

Long-chain unsaturated amino alcohol

Sugars, amino, hydrolysis unsaturated

Unsaturated 5 -oxazolones amino acids

Unsaturated amino alcohols

Unsaturated amino alcohols structures

Unsaturated-1,2-amino alcohols, synthesis

© 2024 chempedia.info