Periodate oxidation glycerol

Periodate oxidation followed by reduction and acid hydrolysis gave rise to glycerol and Xyl in a molar ratio of 88 12. However, when the polyol was reoxidized with periodate and reduced, acid hydrolysis gave rise to glycerol and Xyl in a molar ratio of 94 6, as expected. Interunit hemiacetal formation must have taken place during the initial periodate treatment inhibiting further oxidation. 

Deoxy-l-fluoro-L-glycerol (18) has been prepared by, among other methods, the treatment of 3,4-0-benzylidene-2,5-0-methylene-l,6-di-O-p-tolylsulfonyl-D-mannitol107 (17) with tetrabutylammonium fluoride in acetonitrile, followed by removal of the benzylidene group, periodate oxidation, reduction with borohydride, and hydrolysis. 1,6-Dideoxy-l,6-difluorogalactitol108 was obtained by treatment of 2,3 4,5-di-0-isopropylidene-l,6-di-0-(methylsulfonyl)galactitol with tetra-... 

Periodate oxidation of 5,6-O-isopropylidene-L-gulono-1,4-lactone (9a) gave 2,3-O-isopropylidene-L-glyceraldehyde in 69% yield. This compound was used to prepare 2,3-O-isopropylidene-L-glycerol and it was also condensed with amines and Wittig reagents (34). 

For the analysis of fatty acids amide-linked to GlcN(I), several chemical degradation procedures are available. One comprises periodate oxidation of 0-deacylated and 2H-reducedlipid A (lipid A-OH ). Following permethyl-ation, g.l.c.-m.s. analysis revealed a 2-deoxy-1 -deuterio-1,3-di-O-methyl-2-(iV-methyl-3-methoxyacylamido)glycerol derivative in which the amide-finked fatty acid at GlcN(I) was identified as 14 0(3-OH) in B. pertussis (93), and as 16 0(3-OH) and 18 0(3-OH) in R. trifolii 81). 

The readily available [77, 78] l,6-di-0-benzoyl-3,4-0-benzylidene-2,5-0-methy-lene-D-mannitol has been converted [79] into the benzyl ether (60), which on periodate oxidation and borohydride reduction gives the methylene acetal (61) which readily gives 1 -O-benzyl-L-glycerol for use in lipid synthesis. The acyl derivative (62) has been used [80] in glycolipid synthesis by glycosidation of the hydroxyl group. 

A number of C-6 carboxamide analogues were prepared in which the stereo-chemically complex glycerol side-chain of Zanamivir or 4-amino-4-deoxy-Neu5Ac2en was replaced entirely by secondary or tertiary amides with the general structure of 94 or 95.95,96 These series of compounds were prepared from the C-6 carboxylate 92 (prepared by periodate oxidation of the glycerol side-chain of 91) by amide couling via the activated pentafluorophenyl ester 93 (Scheme 3). 

These treatments convert to ionic substances, and remove, nearly all constituents of natural materials the acid treatments release any inositol present as phosphate, or combined in phospholipids, glycosides, etc. Glycerol remains in the deionized sample, but it can be oxidized separately, or be removed by heat decomposition or by repeatedly evaporating the solution to dryness. Such polyhydric alcohols of greater chain length as erythritol and mannitol, when present, would still interfere. However, corrections can be made for these compounds by determining the formaldehyde which they form on periodate oxidation, or they may be removed by chromatography on filter paper. The micro-periodate method is well suited to the analysis of samples eluted from filter paper, provided that care is exercised to remove the tiny particles of cellulose which are usually found in such eluates. 

The increased sensitivity of the sialic acid glycerol moiety to periodate oxidation as compared with other sugars has been used as a coupling method to label gangliosides selectively (141). 

L-f/ireo-glycerol-l-yl)-pyrazoline-5-one (49) when its solution in alkali was acidified with acetic acid (50). The reaction was further extended to other bis(arylhydrazones) (51), The structure of the phenyl analogue (49) was established by oxidation to the known 3-carboxy-l-phenyl-4-phenylazopyrazolin-5-one (50). Later, on the basis of NMR data (39), the structure of this group of compounds was formulated as the hydra-zones (51). Acylation of 51 aflForded the tri-O-acylated derivatives (51), while periodate oxidation of 51 gave 3-formyl-l-aryl-4,5-pyrazoledione-... 

Support for the occurrence arylglycerol units (54) was obtained in mild hydrolysis studies of lignin [102]. According to studies of the formation of formaldehyde on periodate oxidation [103] only a few percent units with glycerol chain could be present in MWLs. The fact that arylglycerols were formed on enzymatic oxidation of p-hydroxycinnamyl alcohols provided further support for the occurrence of units of type 54 in lignins [104]. Final confirmation of this was later obtained in 2D NMR spectroscopic studies [74]. 

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