Hydrolysis, viii

Reagents i, mesitoyl chloride ii, 03 iii, isopropenylMgBr iv, Ac20-py v, Bu"Li-isopropyl-cyclohexylamine-THF, -78°C vi, HMPA-t-butyldimethylsilyl chloride-THF vii, hydrolysis viii, LiAlH4. 

Scheme 12.8 Synthesis of ferrocene amino acid according to Heinze (i) f-BuLi, -70°C (ii) quenching with iodine (iii) reaction in pyridine with phthalimide and Cu20 as catalyst (iv) hydrazinolysis in ethanol (v) A-acetylation with Ac20 (vi) selective Friedel-Crafts acylation with 2,6-dichlorobenzoyl chloride at the unsubstituted Cp ring (vii) base hydrolysis (viii) removal of the acetyl protection group with hydrochloric acid.

Other syntheses of tropic acid have been accomplished by Spiegel, Miiller, Wislicenus and Bilhiiber, Chambon and Natarajan and Swamina. ( > Of these, the most interesting is the reduction of ethyl formylphenylacetate (VIII) CHO. CHPh. COOC Hj in moist ethereal solution by aluminium amalgam to ethyl tropate, from which the acid (IX) HO. CHj. CHPh. COOH, is obtainable by hydrolysis with baryta. 

We do not list the many hydrolyses of sodium or potassium enolates, and so on, found in Organic Syntheses. The hydrolysis of a Grignard reagent to give an alkane is found at OS II, 478 the reduction of a vinylic tin compound at OS VIII, 381 and the reduction of an alkynylsilane at OS VIII, 281. 

As was noted previously, Hine and Bailey (16, 17) have obtained correlation of rate data for the reaction of tra s-3-substituted acrylic acids and diphenyl-diazomethane with the Hammett equation. Bowden has reported correlation of rate data for the reaction of tra s-3-substituted acrylic acids with diphenyl-diazomethane (59) and the alkaline hydrolysis of trans-3-substituted methyl acrylates (69) with the Hammett equation. Sufficient data are available for nine sets of rate studies. The sets studied are reported in Table VIII. The results of the correlations are given in Table IX. Of the nine sets studied, seven gave... 

Table VIII.—Rates of Hydrolysis of Cellulose and Its Lower Molecular Homologs in 51 Percent Sulfuric Acid at...

Freudenberg, Kuhn and their co-workers showed that both the velocity constants and the courses followed by the hydrolyses of these various polymers can be accounted for by postulating that one or the other or both of the terminal linkages, a and h of Table VIII, in these various species hydrolyze more rapidly than the internal c linkages. All of the latter can be assumed to hydrolyze at the same rate. If, for example, one of the two terminal linkages, a or 6, in an x-mer reacts at a rate equal to cellobiose, 1.07 X10, and the rate for each of the other X —2 linkages corresponds to the initial average rate, 0.305 X10, of hydrolysis of the bonds in cellulose then the calculated... 

By increasing the molar proportion of the mouocarboxylic acid, the yield of (II) is improved. Thus dectrolysis of a mixture of decanoic acid (n-decoic acid capric acid) (V) (2 mols) and methyl hydrogen adipate (VI) (1 mol) in anhydrous methanol in the presence of a little sodium methoxide gives, after hydrolysis of the esters formed, n-octadecane (VII), tetradecanoic or myristic acid (VIII) and sebacic acid (IX) ... 

More recently, Kaiser and coworkers reported enantiomeric specificity in the reaction of cyclohexaamylose with 3-carboxy-2,2,5,5-tetramethyl-pyrrolidin-l-oxy m-nitrophenyl ester (1), a spin label useful for identifying enzyme-substrate interactions (Flohr et al., 1971). In this case, the catalytic mechanism is identical to the scheme derived for the reactions of the cycloamyloses with phenyl acetates. In fact, the covalent intermediate, an acyl-cyclohexaamylose, was isolated. Maximal rate constants for appearance of m-nitrophenol at pH 8.62 (fc2), rate constants for hydrolysis of the covalent intermediate (fc3), and substrate binding constants (Kd) for the two enantiomers are presented in Table VIII. Significantly, specificity appears in the rates of acylation (fc2) rather than in either the strength of binding or the rate of deacylation. 

Reactions of [Pt(dipic)Cl] , dipic = dipicolinate, with 1-methylimida-zole or with 1,2-diaminoethane, monitored in DMF solution, involve replacement of chloride followed by opening of the dipic chelate ring (216). Kinetic data for acid-catalyzed ring opening in hydrolysis of [Pt(dipic)Cl] and of [Pt(glygly)Cl] (217) are compared with those for carboplatin (218) in Table VIII. 

The results of the olefin oxidation catalyzed by 19, 57, and 59-62 are summarized in Tables VI-VIII. Table VI shows that linear terminal olefins are selectively oxidized to 2-ketones, whereas cyclic olefins (cyclohexene and norbomene) are selectively oxidized to epoxides. Cyclopentene shows exceptional behavior, it is oxidized exclusively to cyclopentanone without any production of epoxypentane. This exception would be brought about by the more restrained and planar pen-tene ring, compared with other larger cyclic nonplanar olefins in Table VI, but the exact reason is not yet known. Linear inner olefin, 2-octene, is oxidized to both 2- and 3-octanones. 2-Methyl-2-butene is oxidized to 3-methyl-2-butanone, while ethyl vinyl ether is oxidized to acetaldehyde and ethyl alcohol. These products were identified by NMR, but could not be quantitatively determined because of the existence of overlapping small peaks in the GC chart. The last reaction corresponds to oxidative hydrolysis of ethyl vinyl ether. Those olefins having bulky (a-methylstyrene, j8-methylstyrene, and allylbenzene) or electon-withdrawing substituents (1-bromo-l-propene, 1-chloro-l-pro-pene, fumalonitrile, acrylonitrile, and methylacrylate) are not oxidized. 

Because the metabolism of DEHP was relatively slow, the more readily hydrolyzed 2,4-dichlorophenoxyacetic acid-n-butyl ester was sometimes used for comparison. The hydrolysis of this compound, both by liver preparations and by serum also was inhibited by piperonyl butoxide. Liver homogenates from trout, which had been exposed to piperonyl butoxide in vivo, showed decreased capacity to metabolize DEHP (Table VIII). 

VIII. Hydrolysis of Wood During Sulfite Process I ulping. 186... 

The same procedure has revealed that the aldobionic acid obtained from damson gum and cherry gum by acid hydrolysis has the structure V. Methylation gives the methyl ether VI and when this is subjected to hydrolysis with dilute mineral acid there results 3,4,6-trimethyl-D-mannose (VII) and 2,3,4-trimethyl-D-glucuronic acid (VIII). 

Scheme 5. Reaction conditions i, reductive amination ii, protection of amino group iii, Collins reagent iv, Ph3F CHCioH2i" v, hydrolysis vi, Hg(OAc>2 vii, NaBH4 viii, l-decen-3-one ix, ethanedithiol x, Raney Ni xi, HCl-EtOH.

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