Dialdehydes glyoxal

The slow, rate-limiting step is almost certainly the migration of phenyl that occurs in the initial eOH adduct (135). This is essentially the analogue for 1,2-diketones of the intramolecular Cannizzaro reaction on the 1,2-dialdehyde glyoxal, OHCCHO (p. 217). In the latter... 

Olsen, R. Thorud, S. Hersson, M. Ovrebo, S. Lundanes, E. Greibrokk, T. Ellingsen, D. G. Thomassen, Y Molander, R Determination of the dialdehyde glyoxal in workroom air development of personal sampling methodology. J. Environ. Monit. 2007, 9, 687-694. 

Poly(vinyl alcohol) is readily cross-linked with low molecular weight dialdehydes such as glutaraldehyde or glyoxal (163). Alkanol sulfonic acid and poly(vinyl alcohol) yield a sulfonic acid-modified product (164). 

Macrocycles have been prepared by formation of macrocyclic imines as well as by using variations of the Williamson ether synthesis ". Typically, a diamine or dialdehyde is treated with its counterpart to yield the Schiff s base. The saturated macrocycle may then be obtained by simple reduction, using sodium borohydride, for example. The cyclization may be metal-ion templated. In the special case of the all-nitrogen macrd-cycle, 15, the condensation of diamine with glyoxal shown in Eq. (4.14), was unsuccess-ful ... 

Compounds which contain two oxazirane rings are obtainable from Schiff s bases of glyoxal or terephthalic dialdehyde, e.g. (6). A bifunctional oxazirane is also obtained from ethylene diamine and cyclohexanone (7)d ... 

Suitable dialdehydes can also undergo intramolecular hydride transfer, as in the Cannizzaro reaction of ethan- 1,2-dial (55, glyoxal ) — hydroxyethanoate ( glycollate, 56) anion,... 

Limited data are available on the reaction of diaJdehydes with dinitromethane. Succindialdehyde and glyoxal gave the diaddition products, l,l,6,6-tetranitrohexane-2,5-diol (106) and 1,1,4,4-tetra-nitrobutane-2,3-diol (107), respectively 56). Whether this is due to the low tendency of these dialdehydes to form cyclization products — reaction of glyoxal with nitromethane can give di-addition 57) and cyclization products 58) — or is a general behavior of dinitromethane is not yet apparent. 

From prior attempts at FruA-catalyzed DHAP additions to glyoxal or glutaric dialdehyde no product had been isolated, probably because the dialdehydes can cause cross-linking of the protein and thereby irreversibly destroy its enzymatic activity. On the other hand, hydroxylated aldehydes were assumed to form stable intramolecular hemiacetals in aqueous solution, which may mask the reactivity of free dialdehydes. Using the branched-chain glutaric dialdehyde 38 as a potential precursor to carbon-linked disaccharide mimetics (Scheme 2.2.5.14), we... 

The reaction of indolizines with aldehydes and ketones in the presence of acids yields coloured salts, two of which (43 and 44) are given here for illustration. The salts (45) and (46) have been obtained from the reaction of the pertinent indolizines with formaldehyde and glyoxal respectively. Polymethine dyes, some of which have found application in photography, have been prepared from indolizines and malondialdehyde derivatives or vinylogous dialdehydes (47) was prepared from 1,2-dimethylindolizine and /3-ethoxy-acrolein diethyl acetal (48). 

Several mechanisms34 have been proposed for this reaction. That of Weygand,36 in which an Amadori rearrangement is proposed, has considerable merit.37 Illustrations of unusual osazone formation are described by Bonner and Drisko.38 When phenyl /S-D-xylopyranosyl sulfone (XXII) or /J-D-glucopyranosyl sulfone (XXIV) is oxidized by periodic acid, a dialdehyde oxidation product (XXIII or XXV), which is susceptible toward further oxidation, is obtained. The reaction of XXIII or XXV with phenylhydrazine yields glyoxal phenylosazone and benzenesulfinic acid. Surprisingly, both XXII and XXIII react with phenylhydrazine to form D-xylosazone and D-glucosazone, respectively. 

Cellulose carbamate and its derivatives are able to immobilize enzymes easily with the help of dialdehydes such as dialdehyde starch, glutaraldehyde, and glyoxal [62]. Since cellulose triphenylcarbamate or tricarbanilate prepared... 

In connection with preliminary structural work on the hexitols, an unexpected result arose during attempted identification, by conversion into a (p-nitrophenyl)hydrazone, of the dialdehydes (8) or (9), formed by periodic acid oxidation of tbe anhydrodeoxyhexitols (6) and (7), or (21) and (22). The dialdehydes (8) were cleaved to form glyoxal and a 2-deoxytetrose [isolated as the (p-nitrophenyl)hydra-zone ]. 

Several attempts of FruA-catalyzed DHAP additions to simple aliphatic dialdehydes like glyoxal or glutaric dialdehyde have been reported in the literature, but in no case had a product been isolated and characterized [72,85]. Malonic dialdehyde cannot be used because it tends to enolize under protic conditions and engages in polycondensations. Our own extensive studies corroborate that enzymatic assays indicate a consumption of DHAP, but no defined products result according to t.Lc. or NMR analysis. Problematic also is the fact that aliphatic dialdehydes irreversibly destroy enzymatic activity by protein cross-linking [86,87]. 

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