Pentyl acetate, hydrolysis

Proof that it is indeed this bond that is cleaved was provided by conducting the hydrolysis in water with an enriched content of lsO. Pentyl acetate was hydrolyzed in this iso-topically enriched water. The 1-pentanol product was shown by mass spectrometry to contain only the normal amount of lsO. demonstrating that the alkyl C—O bond was not broken during the reaction. 

Where X = alkoxy and R = H this represents the hydrolysis of an alkyl ester. One of the earliest chemical applications of 018-enriched water was Polanyi and Szabo s demonstration in 1934 that the alkaline hydrolysis of n-pentyl acetate proceeds by acyl-oxygen bond fission. 

Several 4-(3-alkyl-2-isoxazolin-5-yl)phenol derivatives that possess liquid crystal properties have also been obtained (533-535). In particular, target compounds such as 463 (R = pentyl, nonyl) have been prepared by the reaction of 4-acetoxystyrene with the nitrile oxide derived from hexanal oxime, followed by alkaline hydrolysis of the acetate and esterification (535). A homologous series of 3-[4-alkyloxyphenyl]-5-[3,4-methylenedioxybenzyl]-2-isoxazolines, having chiral properties has been synthesized by the reaction of nitrile oxides, from the dehydrogenation of 4-alkyloxybenzaldoximes. These compounds exhibit cholesteric phase or chiral nematic phase (N ), smectic A (S4), and chiral smectic phases (Sc ), some at or just above room temperature (536). 

Of the four possible optical isomers, the (+)-( I )-cw-isomer possesses the most characteristic jasmin odor. Methyl dihydrojasmonate is prepared by Michael addition of malonic acid esters to 2-pentyl-2-cyclopenten-l-one, followed by hydrolysis and decarboxylation of the resulting (2-pentyl-3-oxocyclopentyl) malonate, and esterification of the (2-pentyl-3-oxocyclopentyl)acetic acid [136]. 

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,...

Oxidation of chroman-4-one and its thio analogue with Mn(OAc)3 gives the 3-acetates and subsequent basic hydrolysis yields the 3-hydroxychroman-4-one. Enzymatic hydrolysis of the 0-heterocycle using Amano PS lipase in a phosphate buffer selectively cleaved the (+)-isomer <03TA1489>. Enol ethers derived from chroman-4-one are converted into the 3-hydroxy-chromanone with high enantioselectivity, optimal with the pentyl ether, using a modified Sharpless asymmetric dihydroxylation reaction <03JOC8088>. 

Methyl-l-phenylisoquinoline (380) is obtained when the oxazoline (379) is heated with phosphorus pentoxide. An efficient synthesis of alkylated and dialkylated acetic acids consists in the alkylation of 4,5-dihydro-oxazoline bound to polystyrene, followed by hydrolysis." The asymmetric synthesis of a series of a-alkylphenylacetic acids C H2 +i CHPhC02H ( = 1-5) from the chiral oxazoline (381) has been described. Another example of the use of oxazolines for asymmetric synthesis is the preparation of the optically active binaphthyl (383) from 1-lithionaphthalene and compound [382 R = (—)-menthyl]. The stereoselective formation of threo-dXdoX products (385 = Et, Pr, n-pentyl, etc from the chiral boron compound... 

Hydroxy-6-methyl-2-pentyl-9-oxo-10-oxa-phenanthrene with bromoacetaldehyde diethyl acetal in refluxing dimethylformamide containing potassium carbonate, after 30 minutes gave the corresponding acetal in 90% yield which by way of the aldehyde obtained upon acidic hydrolysis with 2M hydrochloric acid in 89% yield furnished with ethanolic 0.1M sodium hydroxide during 30 minutes the benzofuran shown in 91% yield (ref.137) a cyclisation attributable to the highly reactive... 

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