2-octyl acetal, hydrolysis

In agreement with these findings, the product of hydrolysis of D-2-octyl acetal is D-2-octanol, with an unchanged optical configuration [172]. 

Write equations for the hydrolysis of (a) methyl acetate, (b) ethyl formate, (c) butyl acetate, and (d) octyl acetate. Name all products. 

In experiments carried out on the hydrolysis of octyl acetate with sodium hydroxide as a base and benzyltributylammonium chloride as a PT catalyst, the conversion-time curves were S-shaped, as shown in Figure 19.14 (Glatzer and Doraiswamy, 2000). Such curves are typical of autocatalysis and have important implications in PTC. 

The observation that R-2-octyl acetate yields R-2-octanol with 99% retention rules out the possibility that the reaction occurs by alkyl-oxygen fission [10]. This mechanism is consistent with the normal mode of ester hydrolysis which also occurs by acyl-oxygen fission. Neither amides nor nitriles were affected by superoxide under phase transfer conditions [10]. The data on ester cleavage by superoxide ion is summarized in Table 8.3. 

Fig. 19- The efficiency, q, of the Amberlite IR-120 ion exchanger catalyst in ester hydrolysis as a function of the entropy, S, of the parent hydrocarbon RH or R H of the substituents, (a) Hydrolysis (at 25—45°C) of methyl esters RCOOCH3 [366] 1, acetate 2, chloroacetate 3, benzoate 4, cyclopentanecarboxylate 5, phenylacetate 6, a-naphthylacetate 7, 1-octanoate. (b) Hydrolysis (at 35°C) of acetates CH3COOR [480] 1, methyl 2, ethyl 3, cyclopentyl 4, cyclohexyl 5, 1-butyl 6, 2-pentyl 7, 1 -pentyl 8, 1 -hexyl 9, 1 -octyl,...

The Diels-Alder reaction of 3-methoxyfuran with octyl vinyl ketone took place at room temperature in quantitative yield to afford exclusively the endo cycloadduct (27) (81CC221). Reduction of the carbonyl group with lithium tri-r-butoxyaluminum hydride produced a single alcohol (28). Ozonolysis of the double bond followed by Jones oxidation yielded the lactone ester (29). Hydrolysis of the ester and lead tetraacetate oxidation gave the lactone acetate. This was converted by further hydrolysis and Jones oxidation to the bis-lactone (30), a known intermediate in the synthesis of ( )-isoavenaciolide (Scheme 6). 

The thermal inactivation assays of soluble YLL and immobilized preparations on octyl-agarose, octadecyl epabeads and MANAE agarose were carried out incubating the same amount of lipase in three different buffers at 45°C 25 mM sodium acetate pH 5, 25 mM sodium phosphate pH 7 and 25 mM sodium carbonate pH 9. Periodically, residual enzyme activity was estimated by hydrolysis of pNPB. Soluble enzyme was submitted to the same conditions. 

Enzymes other than CAL B have also been reported to operate under the biphasic conditions. CAL A and CAL B or a lipase from Mucor miehei were tested for the kinetic resolution of glycidol using vinyl acetate or vinyl butyrate. The enzymes were used either suspended in the free ILs or immobilized, when the reactions were carried out in [EMIM][NTf2] [71]. CALAwas inactive, butthe other two enzymes showed activity, albeit at 10-20% of that in the absence of COj whether they were free or immobilized. In general, the supported enzymes showed superior performance [71]. Chymotripsin, a specific protease for aromatic amino acids, was found to catalyze the hydrolysis or transesterification of the ethyl ester of N-acetyl-phenylalanine with propanol in scC02-[RMIM][PF5] (R = butyl or octyl) with or without added water [Eq. (15)]. 

The acid-catalysed hydrolysis of PhC0P(0)(0Et)a is also thought to proceed by a mechanism involving carbonyl addition of water. There is evidence for a phosphorane intermediate in the hydrolysis of MeP(0)(OPh)a. The hydrolysis of P(0)(NH2)3 in acetate buffers has been examined. Studies of micellar catalysts of the dephosphorylation of p-N02CeH40P(0)(0Ph)2 have been reported. The formation of phosphate esters from P(0)Cl3 and p-octyl-phenol in kerosene solution has been reported. The formation and hydrolysis of condensed phosphate species has always been a topic of interest, and there is... 

The insecticide carbaryl (1-naphthyl-A-methylcarbamate, Figure 7.4) has been measured on filter paper exposed during aerial spraying using an ODS-modified silica column and ED (GCE, +0.75 V vs Ag/AgCl) after pre-column alkaline hydrolysis to 1-naphthol. The eluent was acetonitrile-acetic acid-aq. potassium chloride (0.5 mol L ) (50 + 1 + 49). 2-Naphthol was the internal standard. Postcolumn hydrolysis with sodium hydroxide of carbaryl and some other A -methyl-carbamate pesticides has also been employed in measuring crop residues of these compounds. The analytical column used was octyl-modified silica. Elution was... 

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