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Diols reaction with sodium periodate

The preparation of an aldehyde-SAM was achieved by treating the vicinal diol-SAM with sodium periodate. The preparation of an activated tripodal structure on a hydroxyl terminated SAM has been published by Ichimura and coworkers.64 These authors reported the reaction of SAMs formed by mercapto-alkanols such as 2-mercaptoethanol, 6-mercaptohexanol, and 16-mercaptohexadecanol with SiCl4, with the formation of a tripodal derivative bearing a terminal Si—Cl bond amenable to react with methanol or water. [Pg.124]

Periodate oxidation. Aldehyde groups can be easily introduced in most polysaccharides by reaction with sodium periodate. Vicinal diol structures give rise to dialdehydes. For dextran (I) having three adjacent hydroxyl groups in each non-branched anhydro glucopyranoside repeat unit the oxidation is a two step reaction ... [Pg.189]

The most widely used method for the preparation of 1,3,2-dioxathiolane. Y-oxides (cyclic sulfites) 65 bearing C-linked substituents is the reaction of the corresponding 1,2-diols with thionyl chloride in presence of pyridine or Et3N (Scheme 18). More reactive 1,3,2-dioxathiolane. Y,.Y-dioxidcs (cyclic sulfates) 66 are usually obtained by oxidation of sulfites 65 with sodium periodate, which is mediated by mthenium tetroxide generated in situ from a catalytic amount of ruthenium trichloride. Numerous derivatives 65 and 66 were obtained via this approach and its modifications for further transformations, mostly as the synthetic equivalents of epoxides <1997AHC89, 2000T7051> (see also Sections 6.05.5 and 6.05.6, and Tables 1-7). [Pg.184]

The chiral octanediol in turn is converted into the corresponding cyclic sulfate by reaction with thionyl chloride and subsequent oxidation with sodium periodate and a catalytic amount of ruthenium(ni) chloride (0.1 mol%) (eq 2). In the final step, 1,2-diphosphinobenzene is lithiated by treatment with n-butyllithium (n-BuLi 2 equiv, 1.6 mol% in hexane) followed by the addition of the (3R,6R)-octane-3,6-diol cyclic sulfate (2 equiv) and a further addition of 2.2 equiv of n-BuLi. (5,5)-Ethyl-DuPHOS is obtained in a yield of over 70% [78% yield was described for the (R,R)-enantiomer by an analogous method ]. In addition to (5,5)-ethyl-DuPHOS, a variety of related bisphospholanes either linked by an ethylene bridge, or bearing other 2,5-alkyl substituents, or with opposite configuration have been prepared by this methodology. ... [Pg.119]

Oxidative Cleavage Reactions. Among the numerous methods for 1,2-diol cleavage there exist only a few that involve catalytic ruthenium reagents, for example Ruthenium(III) Chloride with Sodium Periodate Attempted selective monooxidation of a 1,2-diol to the hydroxy aldehyde with catalytic TPAP and NMO resulted in carbon-carbon bond cleavage to provide the aldehyde (eq 11). Furthermore, attempted oxidation of an anomeric a-hydroxy ester failed instead, in this case decarboxy-lation/decarbonylation and formation of the lactone was observed (eq 12). However, Dimethyl Sulfoxide-Acetic Anhydride provided the required a-dicarbonyl unit. Retro-aldol fragmentations can also be a problem. ... [Pg.477]

A section on cardenolides would not be complete without mentioning the total synthesis of (+)-digitoxinin by Stork and his co-workers. Protected Wieland-Miescher ketone 66 was converted into compound 67 via formation of the trimethylsilyl enol ether ozonolysis of the enol ether gave a mixture of hydroxyketones, which was reduced to the corresponding diol and then cleaved with sodium periodate to yield dialdehyde intermediate 67. Compound 67 was then elaborated into Diels-Alder precursor 68 in two steps. After completion of the Diels-Alder reaction, four additional steps led to the preparation of intermediate 69, which was ideally set up for a vinyl radical cyclization. Key intermediate 70 was then elegantly converted into (+)-digitoxinin (71). [Pg.567]

Enantiopure aziridines can also be obtained from chiral 1,2-diols. These are converted into cyclic sulfates 68, " or cyclic sulfites 69. These compounds are also cleaved by reaction with lithium azide or sodium azide to azidoalcohols which can then be converted into aziridines as above. The sulfates 68 can be prepared in one pot and in high yield from the diols by reaction with thionyl chloride followed by oxidation with sodium periodate and ruthenium trichloride. Sulfites 69 are available from diols simply by reaction with thionyl chloride. An example of the use of a cyclic sulfate is the preparation of the aziridine 71 in good yield and with high ee from the chiral sulfate 70 (Scheme... [Pg.182]

Regioselective Oxidation. Following the original discovery by David and Thieffrey, several stannylenes have been oxidized by bromine to acyloins (eq 8). Hanessian employed this reaction for the synthesis of a densely functionalized intermediate which was converted into (-i-)-spectinomycin. A detailed study of monooxidation of unprotected carbohydrates has also appeared. Stannylenes are oxidized the same way as diols, with Sodium Periodate and Lead(IV) Acetate. ... [Pg.131]

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],... [Pg.389]


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See also in sourсe #XX -- [ Pg.272 ]




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1.2- diols reactions

Reaction periodate

Sodium periodate

Sodium periodate reaction with

Sodium periodates

Sodium reaction with

With sodium periodate

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