4-hydroxyl-4-methyl-2-pentanone

The other reactions which can be used to estimate the basic property of a solid are the decomposition of 4-hydroxyl — 4-methyl — 2-pentanone (diacetone alcohol) and the isomerizaiton of 1-butene.In the latter reaction, use of isotope tracer gives information regarding the activity of basic sites. 

An attempt to obtain evidence for this hypothesis was made. Reduction of l-hydroxyl-4-pentanone might proceed via a stereochemically less favorable, seven-membered ring intermediate, and the product (1,4-pentanediol) of much less than 30% optically purity might result. Although optically active diol was obtained, no assignment of optical purity could be made since the diol could not be transformed stereo-specifically, despite several attempts, into 2-methyl-tetrahydrothiophene-1-dioxide, whose maximum rotation is known (18). The validity of the above hypothesis thus remains moot. 

The procedure reported here provides a convenient method for the a-hydroxylation of ketones which form enolates under the reaction conditions. The reaction has been applied successfully to a series of para-substituted acetophenones, 1-phenyl-1-propanone, 3-pentanone, cyclopentanone, cyclohexanone, cycloheptanone, cyclododecanone, 2-methyl cyclohexanone, 2-norbornanone and benzalacetone. In the case of a steroidal example it was shown that a carbon-carbon double bond and a secondary hydroxyl group are not oxidized. A primary amino function, as in the case of p-aminoacetophenone, is not affected.5 Similarly, a tertiary amino ketone such as tropinone undergoes the a-hydroxy at ion reaction.5... 

Figure 5. Stereospecific hydroxylation of cyclopentane carboxylic acid (a) and 4-methyl-2-pentanone (b) by two fungus species using the docking/protecting group concept.

The results of Barltrop and Coyle , on the photolysis of aliphatic ketones in solution at 3130 A, support the explanation suggested by Wagner and Hammond for the low quantum yields. The overall quantum yield for disappearance of 2-pentanone, 2-octanone and 5-methyl 2-octanone was found to increase and approach unity in hydroxylic solvents. This increase can be attributed to the solvation of the hydroxy biradical intermediate. Since, however, the solvent effect was not observed for products originating from excited singlet molecules, it is probably only the triplet state which decomposes via biradicals. 

Primary amines form Schiff bases, (CH3 )2C=NR. Ammonia induces an aldol condensation followed by 1,4-addition of ammonia to produce diacetone amine (from mesityl oxide), 4-amino-4-methyl-2-pentanone [625-04-7], (CH3)2C(NH2)CH2COCH3, and triacetone amine (from phorone), 2,2,6,6-tetramethyl-4-piperidinone [826-36-8]. Hydroxyl amine forms the oxime and hydrazine compounds (RNHNH2) form hydrazones (RNHN=C(CH3 )2). Acetone and nitrous acid give the isonitroso compound which is the monoxime of pyruvaldehyde [306-44-5], CH3COCH=NOH. 

The procedure reported here provides a convenient method for the a-hydroxylation of ketones which form enolates under the reaction conditions. The reaction has been applied successfully to a series of para-substituted acetophenones, 1-phenyl-1-propanone, 3-pentanone, cyclopentanone, cyclohexanone, cycloheptanone, cyclododecannne, 2-methyl cyclohexanone, 2-... 

Polymer Synthesis. Polyethylene glycol (PEG) 600,1000, and 1500 were obtained from Aldrich Chemical Company and dried by azeotroping with toluene. Molecular weights for the polyethylene glycols were determined from hydroxyl numbers. DieSiylene glycol (DEG) from Fisher Scientific was purified by vacuum distillation over metallic sodium. Hexamethylene diisocyanate (HMDI) from Aldrich Chemical Company was vacuum distilled. Dicyclohexylmethane-4,4 -diisocyanate (DCDI) (Desmodur W) from Mobay Chemical Company was used as received. Dibutyltin bis-(2-ethylhexanoate) from Kodak was stored over phosphorus pentoxide. N,N-dimethylformamide (DMF) from EM Science and 4-methyl-2-pentanone from Aldrich Chemical Company were dried over 3A molecular sieves. 

O rji, L.N., and D.A. Stone (1992), Relative rate constant measurements for the gas-phase reactions of hydroxyl radicals with 4-methyl-2-pentanone, trans-4-octene, and trans-2-heptene, Int. J. Chem. Kinet., 24, 703-710. 

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