Periodic acid cleavage carbohydrates

Periodic acid cleavage of vicinal diols is often used for analytical purposes as an aid m structure determination By identifying the carbonyl compounds produced the con stitution of the starting diol may be deduced This technique finds its widest application with carbohydrates and will be discussed more fully in Chapter 25... 

Periodic Acid Cleavage of Carbohydrates Another method used to determine the size of carbohydrate rings is cleavage by periodic acid. Recall that periodic acid cleaves vicinal diols to give two carbonyl compounds, either ketones or aldehydes, depending on the substitution of the reactant (Section 11-1 IB). 

Determine the structure of an unknown carbohydrate based on its reactions. Determine its ring size from the methylation and periodic acid cleavage reactions. Problems 23-57, G3, G4, G5, and 66... 

Periodic Acid Cleavage of Carbohydrates Another method used to determine... 

Use the information gained from these reactions to determine the structure of an unknown carbohydrate. Use the information gained from methylation and from periodic acid cleavage to determine the ring size. 

Most of the compounds that had been reported (before March, 1942) to show cleavage oxidation by periodic acid are recorded in the table the substances are listed alphabetically in the following groups of related compounds (1) carbocyclic compounds (2) carbohydrates (3) a-diketones and a-ketols (4) hydroxyamino compounds (5) polyhydroxy and hydroxyketo acids (6) polyhydroxy alcohols (7) steroids (8) miscellaneous compounds. French journals after May, 1940, and the majority of other foreign publications after June, 1941, were unavailable for the survey. 

Like other compounds that contain two or more - OH or - O groups on adjacent carbon atoms, carbohydrates undergo oxidative cleavage by periodic acid, HIO4 (Sec. 16.12). This reaction, introduced in 1928 by L. Malaprade (at the University of Nancy, France), is one of the most useful tools in modern research on carbohydrate structure. 

The glycol-cleavage oxidation reaction (Scheme 3.366) is the major area of application of periodic acid, which is particularly important in carbohydrate chemistry [1316,1317]. 

Sodium metaperiodate, NaI04, is a common, commercially available oxidant widely used in organic synthesis. As with periodic acid, sodium metaperiodate can be used for the glycol-cleavage oxidation reaction, which is particularly important in carbohydrate chemistry. Scheme 3.370 shows a representative example of a glycol-cleavage oxidation with NaI04 this reaction has been used in the synthesis of (25,45)-4-hydroxyproline... 

Carbohydrates and their derivatives. There are a great many simple carbohydrates available, but one of the most useful is mannose. Reduction to the alcohol gives the C2-symmetric compound mannitol, which can be converted to a useful aldehyde by selective protection as a bis-acetal with acetone and a Lewis acid. Cleavage of the remaining diol with sodium periodate gives two equivalents of a useful protected form of glyceraldehyde. 

Oxidative cleavage of vicinal diol functions in carbohydrates occurs with periodic acid (HIO4) or sodium metaperiodate (NaI04). The reaction proceeds through a cyclic intermediate and is similar to what we encountered with diols in Section 15.11. 

From Chiral Non-carbohydrates - A section on amino-sugars has been included in a review of the synthesis of monosaccharides from non-carbohydrate sources. L-Ristosamine 42 was synthesized by addition of the Cs-synthon 40 (which contains a masked aldehyde function that can be readily demasked by mild acid hydrolysis) to the L-lactaldehyde derivative 41 (Scheme 11). The TBSOP adduct 43 (Vol.27, p.ll4), derived from 2,3-< -isopropylidene-D-glycer-aldehyde, has been converted into 3-amino-3-deoxy-D-altrose 46 by a route involving cis-hydroxylation of its unsaturated lactam moiety and periodate cleavage between C-6 and C-7 of the derived heptitol derivative 45 as key steps (Scheme 12). 3-Amino-3-deoxy-L-allose was obtained by converting 43 to its C-3... 

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