1.2- Diols sodium periodate

The oxidative cleavage of v/c-diols to give two carbonyl functions (Eq. 5.3) by periodates was first observed by Malaprade and has since been widely applied to the carbohydrate area.50 Since both the reagent sodium periodate and the carbohydrate substrate are water soluble, the reaction is usually carried out in aqueous media.51 The reaction has been applied to polysaccharides such as starch.52 The periodate oxidations of sodium alginate in water as well as a dispersion in 1 1 ethanol-water mixture have been compared.53 Because sodium alginate forms a highly viscous solution, the oxidation was observed to be more extensive in ethanol-water. 

Figure 4.7 DST may be used to crosslink amine-containing molecules, forming amide bond linkages. The central diol of the cross-bridge is cleavable by treatment with sodium periodate.

Sodium periodate also may affect tryptophan residues in some proteins. The oxidation of tryptophan can result in activity losses if the amino acid is an essential component of the active site. For instance, avidin and streptavidin may be severely inactivated by treatment with periodate, since tryptophan is important in forming the biotin-binding pocket. In addition, many other amino acid residues are susceptible to oxidation by periodate (Chapter 1, Section 1.1). Limiting the time of oxidation is important to restricting oxidation to diol groups while not affecting other protein structures. 

Figure 8.2 Crosslinkers containing a diol group in their cross-bridge design may be cleaved by oxidation with sodium periodate.

Microgels prepared in that way are hydrophilic, stable and do not tend to agglomerate. By oxidation of the diol group with sodium periodate a free aide-... 

A stereoselective total synthesis of ( )-hirsutine has been developed by Brown et al. (179). Catalytic hydrogenation of hydroxycyclopentenone 327, prepared previously (180), afforded a mixture of isomeric diols 328, which were quantitatively cleaved by sodium periodate to supply 329. Reductive amination of 329 with tryptamine resulted in tetrahydropyridine 330, which upon treatment with aqueous methanol in the presence of hydrochloric acid gave indolo-[2,3-a]quinolizine 321 with pseudo stereochemistry. Conversion of 321 to ( )-hirsutine was accomplished in a similar manner by Wenkert et al. (161) via selective reduction with diisobutylaluminum hydride and methylation with methanol (179). 

In their pioneering work. Just and co-workers have described many interesting transformations of the Diels-Alder adducts of furan to methyl nitroacrylate (77 + 77 ) and to dimethyl acetylenedicarboxylate (53). The mixture of racemic adducts 77 + 77 was hydroxylated into the exo-cis-diols 125 + 125 , separable by crystallization. Treatment of the isopropylidene acetal obtained from 125 with diazabicyclo[5.4.0]undec-5-ene (DBU) gave a high yield of alkene 126. Ozonolysis followed by a reductive work-up with dimethylsulfide, then with NaBH4, gave a mixture of epimeric triols 127. Cleavage with sodium periodate afforded 2,5-anhydro-3,4-0-isopropylidene-DL-allose (128) in 15 % yield, based on methyl 2-nitroacrylate used. TTie same allose derivative was obtained from adduct 53. ... 

The (—)-anisomycin work is presented in Scheme 35. Its key step centered around the formation of a pyrrolidine ring that possessed all three of the asymmetric centers present in the target this was done by nucleophilic displacement of a 3-tosyloxy function in an appropriately functionalized 6-amino-6-deoxy-p-i.-talose derivative, whose 1,2-diol was later released and oxidatively cleaved with sodium periodate. Grignard coupling, O-acetylation, and catalytic hydrogenation then furnished the desired natural-product target. 

Alternatively, the cyclobutanones can be made by two-step procedures, i.e. osmium(VIII) oxide oxidation to the diol followed by further oxidation either by lead(IV) acetate 85 or sodium periodate,86,87 or epoxidation followed by oxidation with periodic acid,15,63 are reported to yield the ketones. 

Aldehydes and ketones often can be prepared by oxidation of alkenes to 1,2-diols (Sections 11-7C and 11-7D), followed by oxidative cleavage of the 1,2-diols with lead tetraethanoate or sodium periodate. For example,... 

Exercise 16-37 An elegant modification of the two-step procedure to prepare ketones from alkenes by hydroxylation and oxidative cleavage of the diol formed uses a small amount of potassium permanganate (or osmium tetroxide, 0s04) as the catalyst and sodium periodate as the oxidizing agent ... 

Exercise 16-38 Write mechanisms for the oxidative cleavage of 1,2-diols by lead tetraethanoate and sodium periodate based on consideration of the mechanism of chromic acid oxidation (Section 15-6B). ... 

In a first step, the TBS ether is subjected to acid cleavage with copper sulfate in acetone containing a catalytic amount of glacial acetic acid. The resulting diol is then protected as an acetunide. Next, the double bond is oxidatively cleaved with sodium periodate and a catalytic amount of osmium tetroxide to give aldehyde 5. 

The use of cyclic sulfates in synthetic applications has been limited in the past because, although cyclic sulfites are easily prepared from diols, a convenient method for oxidation of the cyclic sulfites to cyclic sulfates had not been developed. The experiments of Denmark [70] and of Lowe and co-workers [71 ] with stoichiometric ruthenium tetroxide oxidations and of Brandes and Katzenellenbogen [72a] and Gao and Sharpless [68] with catalytic ruthenium tetroxide and sodium periodate as cooxidant have led to an efficient method for this oxidation step. Examples of the conversion of several diols (67) to cyclic sulfites (68) followed by oxidation to cyclic sulfates (69) are listed in Table 6D.7. The cyclic sulfite/cyclic sulfate sequence has been applied to 1,2-, 1,3-, and 1,4-diols with equal success. Cyclic sulfates, like epoxides, are excellent electrophiles and, as a consequence of their stereoelectronic makeup, are less susceptible to the elimination reactions that usually accompany attack by nucleophiles at a secondary carbon. With the development of convenient methods for their syntheses, the reactions of cyclic sulfates have been explored, Most of the reactions have been nucleophilic displacements with opening of the cyclic sulfate ring. The variety of nucleophiles used in this way is already extensive and includes H [68], [68,73-76], F" [68,72,74], PhCOCT [68,73,74], NOJ [68], SCN [68],... 

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