Di hydroxyacetone

Hydroxyl groups are stable to peracids, but oxidation of an allylic alcohol during an attempted epoxidation reaction has been reported." The di-hydroxyacetone side chain is usually protected during the peracid reaction, either by acetylation or by formation of a bismethylenedioxy derivative. To obtain high yields of epoxides it is essential to avoid high reaction temperatures and a strongly acidic medium. The products of epoxidation of enol acetates are especially sensitive to heat or acid and can easily rearrange to keto acetates. 

Similar hydroxylation-oxidations can be carried out using a catalytic amount of osmium tetroxide with A-methylmorpholine oxide-hydrogen peroxide or phenyliodosoacetate." A recent patent describes the use of triethylamine oxide peroxide and osmium tetroxide for the same sequence. Since these reactions are of great importance for the preparation of the di-hydroxyacetone side-chain of corticoids, they will be discussed in a later section. 

The determination of 17-ketosteroids is most often determined in the clinical laboratory by the Zimmerman reaction, in which the ether-extracted material is allowed to react with m-nitroaniline to yield a colored product. Thus, any compound with the 17-keto basic structure such as reserpine, morphine, ascorbic acid, or their metabolites will interfere. The Porter-Silber reaction used in the determination of 17,21-dihydroxysteroids is also not specific, and the reaction requires a di-hydroxyacetone side chain. Paraldehyde, chloral hydrate, meprobromate, and potassium iodide have been found to interfere, and patients should be maintained free of these drugs for 24-48 hours before the urine collection (Bll). 

Second, some reactants that make up a free inter-converting pool are combined into a single metabolite [204], For example the two glycolytic intermediates di-hydroxyacetone phosphate and glyceraldehyde 3-phosphate are represented by the lumped species T3P (for triose-3-phosphate). 

Peroxisome proliferators are also involved in two other metabolic pathways of importance to lipid metabolism. Peroxisomes contain the most of di-hydroxyacetone phosphate acetyltransferase and alkyldihydroxyacetone phosphate synthetase activities. Therefore, they are responsible for initiating most ether glycerolipid biosynthesis. These enzymes are also moderately induced by peroxisome proliferators. Induction of cytochrome P450s by peroxisome proliferators will be addressed separately. 

Miscellaneous.—Tetramethyl-bismethylenedioxy-derivatives (780) of the di-hydroxyacetone side-chain are readily prepared by the action of acetone and perchloric acid. As protecting groups they appear to have advantages over the well-known bismethylenedioxy-compounds, especially in being more readily hydrolysed. NJV-Dimethylhydrazones can be used to protect oxo-groups, during oxidation, reduction, hydroboronation, hydrolysis, etc., elsewhere in the molecule. 

Glyceryl-a-monochlorohydrin 96-26-4 Biogir -DHA Di hydroxyacetone Dihydroxyacetone No. 10150 Nanospheres 100 Dihydroxyacetone Pro-DHA ... 

The photosynthetic product of the Calvin cycle, di-hydroxyacetone phosphate (DiHOAcP), is transports from the bundle sheath chloroplasts to the < o-plasm where it is converted into sucrose (see Hg.1 of the entry Calvin cycle) then exported to the growing parts of the plant via the phloem of the adjacent vascular bundle. 

In addition to the condensation of the three components, stepwise syntheses have also been successful. For example, dibromopropionaldehyde was condensed with pyridine to form iV-(2-formyl-2-bromoethyl)pyridinium bromide which upon reaction with the triaminohydroxypyrimidine formed Ar-(2-amino-4-hydroxy-6-pteridyl)-methylpyridinium bromide . Also, di-hydroxyacetone was condensed directly with the p5n imidine to form 2-ami-... 

The diastereoselectivity of the Baylis-Hillman reaction was investigated by attaching chiral auxiliaries to a,-unsaturated ketones [216]. The use of the 4-isopropyloxazoladinone chiral auxiliary in [EMIM][OTf] gave rise to very low di-astereomer ratios (45 55) (Scheme 5.2-88). The authors also describe a proline -catalyzed aldol reaction of acetone, butanone, hydroxyacetone and chloroacetone with a chiral imine and obtain up to 9 1 diastereomer ratios. 

The aldol reaction between functionalized ketones, such as hydroxyacetone (8a, 29.2 equiv.) with high electrophilic aldehydes, was possible using different A -terminal proline peptide derivatives (10-20 mol%) in mixtures of THF water at 0°C. Among ten screened different di-, tri-, tetra-, penta- and hexapeptides, catalysts 120a, b (Fig. 4.20) with lipophilic phenylalanine residues gave the best performance, providing mainly regioisomers /xo-10 (Scheme 4.3, R =H) in 82 and 76% yield, and 82 and 87% ee, respectively [207]. 

More specific cycfizations are shown in Scheme 56. Carbonate of hydroxyacetone is not an allyl carbonate, but it can give rise to an 17 -l-oxaallylpalladium complex, which reacts with rigid olefins to afford cyclopropylketones.f ° Monocarbonate of cis-butene-l,4"di i forms a zwitterionic r/ -allylpalladium complex, which reacts as a dipole with Ceo to afford a vinyltetrahydrofuran derivative of fullerene. A... 

---