Hydrolysis structure

Berghuis, A.M., et al. Structure of the GDP-Pi complex of Gly203-Ala Giai a mimic of the ternary product complex of Ga-catalyzed GTP hydrolysis. Structure 4 1277-1290, 1996. 

Disaccharides are carbohydrates that yield two monosaccharide molecules on hydrolysis. Structurally, disaccharides are glycosides in which the alkoxy group attached to the anomeric carbon is derived from a second sugar molecule. 

Multiple recognition and catalysis in ATP hydrolysis with increased ATP/ADP selectivity has been achieved with a multifunctional anion receptor containing a macrocyclic polyamine as anion binding site, an acridine group as stacking site and a catalytic site for hydrolysis (structure 82) [4.27]. Phosphoryl transfer is accelerated by other types of hydrogen-bonding receptors [5.24a]. 

B. Partial Acid Hydrolysis Structural Analys s of Proteins. ... 

Formaldehyde treatment causes wood to become brittle. This embrittlement may be caused by the short inflexible cross-linking unit of the -O-C-O- type. If the inner carbon unit were longer, there would be more flexibility in this unit, and the embrittlement should be reduced. Most of the loss in wood strength properties is probably caused by the hydrolysis structural cellulose units with a strong acid catalyst. 

Fig. 7 Mulliken population analysis from CNDO/2 calculations for "cyclic phosphate TBP [61c] and acyclic TBP [61b] intermediates. The TBP [61c] possesses an app interaction with the scissile endocylic P—O bond and models the TBP for MEP hydrolysis. Structure [61c] was not examined, but is given by interpolation of other conformers (Gorenstein et al., 1977a).

In addition to the separate or combined effects of heat, oxygen, and radiation, polymers may deteriorate due to exposure to water (hydrolysis) or different types of chemical agents. Condensation polymers like nylons, polyesters, and polycarbonates are susceptible to hydrolysis. Structural alteration of some polymers may occur as a result of exposure to different chemical environments. Most thermoplastics in contact with organic liquids and vapors, which ordinarily may not be considered solvents for the polymers, can undergo environmental stress cracking and crazing. This may result in a loss of lifetime performance or mechanical stability and ultimately contribute to premature mechanical failure of the polymer under stress. 

Strecker synthesis (Section 23.2) A synthesis of amino acids using an aldehyde, cyanide, and ammonia, followed by hydrolysis. Structural isomers (Section 2.7) Molecules of the same formula... 

Based on spectral analogies with known five-membered ring hop derivatives and in view of the formation of oxyhumulinic acid (25, Fig. 20) by alkaline hydrolysis, structure 24 has been proposed for humulinone or 2-(3-methylbutanoyl)-5-(3-methyl-2-butenyl)-3,4,5-trihydroxy-4-(4-methyl-3-pentenoyl)-2-cyclopentenone (Fig. 20) (11). The structure of oxyhumulinic acid (melting point 72°C) has been established... 

Hammen equation A correlation between the structure and reactivity in the side chain derivatives of aromatic compounds. Its derivation follows from many comparisons between rate constants for various reactions and the equilibrium constants for other reactions, or other functions of molecules which can be measured (e g. the i.r. carbonyl group stretching frequency). For example the dissociation constants of a series of para substituted (O2N —, MeO —, Cl —, etc.) benzoic acids correlate with the rate constant k for the alkaline hydrolysis of para substituted benzyl chlorides. If log Kq is plotted against log k, the data fall on a straight line. Similar results are obtained for meta substituted derivatives but not for orthosubstituted derivatives. 

Prepared generally by ester interchange from polyvinylacelate (ethanoate) using methanol and base also formed by hydrolysis of the acetate by NaOH and water. The properties of the poly(vinyl alcohol) depend upon the structure of the original polyvinyl acetate. Forms copolymers. Used as a size in the textile industry, in aqueous adhesives, in the production of polyvinyl acetates (e.g. butynal) for safety glasses. U.S. production 1980... 

The half-lives for these four compounds taken from the literature allowed the estimation of the Four reaction rates necessai to model their degradation [18], As a first approximation, the rate of hydrolysis of the C-Cl bond of all Four, -triazine compounds was assumed to be the same and to be 5.0 x 10 s on the basis of literature precedence. This approximation seems reasonable as the four structures differ only in the alkyl groups at a site quite remote from the C-CI bond. Furthermore, among the Four reaction steps hydrolysis is the slowest anyway. 

It is frequently advisable in the routine examination of an ester, and before any derivatives are considered, to determine the saponification equivalent of the ester. In order to ensure that complete hydrolysis takes place in a comparatively short time, the quantitative saponi fication is conducted with a standardised alcoholic solution of caustic alkali—preferably potassium hydroxide since the potassium salts of organic acids are usuaUy more soluble than the sodium salts. A knowledge of the b.p. and the saponification equivalent of the unknown ester would provide the basis for a fairly accurate approximation of the size of the ester molecule. It must, however, be borne in mind that certain structures may effect the values of the equivalent thus aliphatic halo genated esters may consume alkali because of hydrolysis of part of the halogen during the determination, nitro esters may be reduced by the alkaline hydrolysis medium, etc. 

Another method for the hydroxylation of the etliylenic linkage consists in treatment of the alkene with osmium tetroxide in an inert solvent (ether or dioxan) at room temperature for several days an osmic ester is formed which either precipitates from the reaction mixture or may be isolated by evaporation of the solvent. Hydrolysis of the osmic ester in a reducing medium (in the presence of alkaline formaldehyde or of aqueous-alcoholic sodium sulphite) gives the 1 2-glycol and osmium. The glycol has the cis structure it is probably derived from the cyclic osmic ester ... 

East Indian sandalwood oil contains a hydrocarbon given the name santene (C9H14) Ozona tion of santene followed by hydrolysis gives compound A What is the structure of santene" ... 

Sabinene and carene are isomeric natural products with the molecular formula CjoHig (a) Ozonolysis of sabinene followed by hydrolysis in the presence of zinc gives compound A What IS the structure of sabinene" What other compound is formed on ozonolysis" (b) Ozonoly SIS of A carene followed by hydrolysis in the presence of zinc gives compound B What is the structure of A carene" ... 

The hydrolysis of sulfonate esters of 2 octanol is stereospecific and proceeds with complete inversion of configuration Write a structural formula that shows the stereochemistry of the 2 octanol formed by hydrolysis of an opti cally pure sample of (S) (+) 1 methylheptyl p toluenesulfonate identify the prod uct as / or S and deduce its specific rotation... 

Under conditions of photochemical chlorination (CH3)3CCH2C(CH3)3 gave a mixture of two monochlorides in a 4 1 ratio The structures of these two products were assigned on the basis of their SnI hydrolysis rates in aqueous ethanol The major product (compound A) underwent hydrolysis much more slowly than the minor one (compound B) Deduce the structures of com pounds A and B... 

This cleavage reaction is more often seen in structural analysis than in synthesis The substitution pattern around a dou ble bond is revealed by identifying the carbonyl containing compounds that make up the product Hydrolysis of the ozonide intermediate in the presence of zinc (reductive workup) permits aide hyde products to be isolated without further oxidation... 

Hydrolysis of a compound A in dilute aqueous hydrochlonc acid gave (along with methanol) a compound B mp 164—165°C Compound B had the molecular formula CigHig04 it exhibited hydroxyl absorption in its IR spectrum at 3550 cm but had no peaks in the carbonyl region What IS a reasonable structure for compound B" ... 

This difference m reactivity especially toward hydrolysis has an important result We 11 see m Chapter 27 that the structure and function of proteins are critical to life Itself The bonds mainly responsible for the structure of proteins are amide bonds which are about 100 times more stable to hydrolysis than ester bonds These amide bonds are stable enough to maintain the structural integrity of proteins m an aqueous environment but susceptible enough to hydrolysis to be broken when the occasion demands... 

Hydrolysis of either A or B yields RNHCH2CH2OH and p nitrobenzoic acid Suggest a reason able structure for compound B and demonstrate your understanding of the mechanism of this reaction by wnting the structure of the key intermediate in the conversion of compound A to com pound B... 

Of all the monosaccharides d (+) glucose is the best known most important and most abundant Its formation from carbon dioxide water and sunlight is the central theme of photosynthesis Carbohydrate formation by photosynthesis is estimated to be on the order of 10 tons per year a source of stored energy utilized directly or indi rectly by all higher forms of life on the planet Glucose was isolated from raisins m 1747 and by hydrolysis of starch m 1811 Its structure was determined in work culmi nating m 1900 by Emil Fischer... 

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