1.3- Dihydroxy-2-propanone

Propanone, 1,3- dihydroxy -, phosphate, 215, 239-243, 247, 248, 252 Proteins, complexes with chitin, 374 proportion of, in arthropod cuticles, 373... 

An interesting compound having a structure analogous to that of d-fructopyranose is l,3-dihydroxy-2-propanone ( dihydroxyacetone, 24) ... 

AH,B units at opposite ends of the molecule, just as in the case of l,3-dihydroxy-2-propanone (see Section II,3,a,ii), so that the molecule cannot align itself correctly on the receptor surface.Odorant molecules have been observed to behave similarly. The poor polarization of the taste receptor is enhanced by the combined effect of (a) the absence of a ring-oxygen atom, and hence a polar center, and (b) the presence of hydrophobic, methylene groups. 

The scope of the reaction was considerably enlarged in 1935, when Clutterbuck and Reuter6 observed that the compound tetrahydroterrein, derived from the mold metabolite terrein, consumes more than the calculated amount of periodate per mole. They found that 1,2-diketones and a-hydroxy ketones are also oxidized under the conditions used by Malaprade. Although this type of oxidation had been earlier noted [in a study7 of the action of periodate on 1,3-dihydroxy-2-propanone (dihydroxyace-tone)], Clutterbuck and Reuter made a more thorough exploration of the reaction.6 In a series of model compounds, Ri and R2 were varied from... 

Hypothesis (A) is in contradiction with the experimental evidence, since glycolaldehyde andl, 3-dihydroxy-2-propanone (dihydroxyacetone)9 16 react in the same way as do the sugars. It is evident that these compounds do not possess two contiguous hydroxyl groups. Moreover, when methyl trans-0-(/3-D-glucopyranosyl)acetoacetate enol (LXIV) was treated with zinc chloride under the conditions used by West and by Garda Gonzalez, a... 

A simple synthesis of the branched chain sugar, 2-C-methyl-D,L-lyxofuranoside 17 has been achieved by using the tin(ll) enolate of a I 3-dihydroxy-2-propanone derivative and methyl pyruvate (23). 

It seems unlikely that this reaction could occur in quite the same way as in the laboratoryaldol reaction, because the enolate anion of the donor molecule (dihydroxypropanone) is not expected to be formed in significant amount of the pH of living cell. In fact there is strong evidence that the enzyme behaves as amino (ENH2) compound and reacts with carbonyl group of dihydroxy propanone to form an imine. This implies that the imine form of dihydroxy propanone is a key intermediate in the overall aldol-type addition. 

The isolation of uridine 5 -(l,3-dihydroxy-2-propanone pyrophosphate) from a Pneumococcus strain has been reported.202... 

Possibly not found because of the small quantities used. "Also identified l,3-dihydroxy-2-propanone, DL-glucose, DL-fructose, DL-mannose, DL-arabinose, DL-lyxose, and DL-xylose (and, possibly, DL-ribose). 

The almost exclusive formation of 4(5)-(hydroxymethyl)imidazole (27) from D-fructose, l,3-dihydroxy-2-propanone, and D-fructose-containing compounds (for example, sucrose) is to be expected... 

These conclusions are borne out by the data on some phosphorylated ketoses83 that cannot form pyranoses or furanoses. 5,6-Dideoxy-D-fhreo-hexulose 1-phosphate (1) contains 96% (by i.r.) or 91% (by n.m.r.) of the keto form, and D-en/fhro-pentulose 1,5-bisphosphate (2) contains 84% (by i.r.) or 88% (by n.m.r. spectroscopy80 ) in aqueous solution in the hydrates, there would be 1,3-parallel interactions. There are no such interactions in the hydrate of l,5-dihydroxy-2-pentanone 1,5-bisphosphate (3), but here one of the carbon atoms vicinal to the carbonyl group carries no hydroxyl group, and there is 84% of the keto form in equilibrium. l,3-Dihydroxy-2-propanone phosphate has two neighboring hydroxyl groups and no 1,3-parallel interactions only 55% is in the keto form and 45% is present as the hydrate.83,84... 

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