Ribitol 1.5- anhydro

The synthesis of all positional isomers of partially methylated-acetylated or methylated-benzoylated derivatives of 1,4-anhydro-D-xylitol, 1,4-anhydro-L-fucitol, 1,4-anhydro-D-ribitol, 1,5-anhydro-D-mannitol, 1,5-anhydro-D-gJu-citol, and IjS-anhydro-D-galactitoP" have been described. The compounds should be useful as standards for determining the primary structure of polysaccharides after reductive cleavage. 

Reference has already been made to the formation of anhydro sugars under the influence of acid (see Section XI, p. 87). In a similar manner, alditols may be converted into anhydroalditols, and these may be difficult to distinguish from other polyhydric compounds of low molecular weight. Such a problem arises in the hydrolyzates of cell walls, where ribitol and glycerol are present. It has been shown, however, by Gregory that glycerol and an anhydroribitol may be separated readily as their trimethylsilyl ethers.401... 

Cleavage of the dithioacetal groups from the products, followed by reduction of the resultant carbonyl derivatives (46, 49, 52) with sodium borohydride leads,68 with the three compounds (45, 48, and 51), to 1,4-anhydro-L-ribitol (2,5-anhydro-D-ribitol) (47), 1,4-anhydro-L-xylitol (2,5-anhydro-D-xylitol) (50), and 1,4-anhydro-D-arabinitol (2,5-anhydro-D-lyxitol) (53), identified by comparison with their enantiomorphs, 1,4-anhydro-D-ribitol,69 1,4-anhydro-D-xylitol,70 and 1,4-anhydro-L-arabinitol. 71... 

The 2(/ )-tetrahydro-2-furaldehyde (112) is reduced115 by sodium borohydride to the corresponding alcohol (114). 2,5-Dihydrofurfuryl alcohol can be prepared, starting from 2,5-anhydro-l-0-benzoyl-3,4-di-O-p-tolylsulfonyl-D-ribitol, by using the Tipson-Cohen112 method for introducing the 3,4-double bond, with subsequent saponification of the ester.116... 

That the anhydro product from ribitol is a derivative of 1,4-tetra-hydrofuran was established10 from the results of periodate oxidation (consumption of 1 mole of periodate per mole, with no formation of... 

In contrast to ribitol and xylitol (which form a dl mixture on anhydride formation because of their molecular symmetry), D-arabinitol may, in principle, on heating with acid, give two different anhydrides, namely, a 1,4-anhydroarabinitol ora 2,5-anhydroarabinitol (1,4-anhydro-lyxitol), as the following reaction sequence illustrates. 

The enantiomorph, also a syrup, was synthesized from 3,6-anhydro-4,5-O-isopropylidene-D-mannitol18 by periodate oxidation to the corresponding D-arabinose derivative, followed by reduction in the presence of Raney nickel.17 2,5-Anhydro-D-xylitol, 2,5-anhydro-D-ribitol, and 2,5-anhydro-D-lyxitol (1,4-anhydro-D-arabinitol)19,20 were... 

Also, di-O-acetyl-L-arabinal was converted into the corresponding anhydro-L-ribitol derivative (see also, pp. 195-197). 

Hedgley and Fletcher80 found that 1,4-anhydro-D-ribitol and 1,4-anhydroerythitol are comparatively stable to liquid hydrogen fluoride at 18°. 

Although these anhydropentitols lack the cis-trans triple-ester arrangement, the following respective intermediates from 1,4-anhydro-tri-O-benzoyl-D-ribitol and tri-0-acetyl-l,4-anhydro-D-xylitol were proposed, in order to account for the epimerizations that occur. 

The competitive inhibition of aldolase by a number of structural analogs of D-ftuctose 1,6-diphosphate has been investigated.120 Among these analogs were 1,4-anhydro-DL-ribitol 5-phosphate, 1,4-anhydro-DL-xylitol 5-phosphate, 1,4-anhydro-D-arabinitol 5-phosphate, 2,5-anhydro-D-mannitol 1,6-diphosphate, and 2,5-anhydro-D-glucitol 1,6-diphosphate. Their respective, enzyme-inhibitor,... 

Access to 1,4-anhydro-D-alditols by radical reduction has received only limited attention, but the most detailed work concerns the reduction of protected glycofuranosyl isocyanides on heating for 2 h at 80 °C in toluene in the presence of /J-BU3S11H (2 eq) and AIBN.188 In particular, 2,3,5-tri-0-benzoyl-0-D-ribofuranosyl isocyanide (53) was converted in 78% yield into l,4-anhydro-2,3,5-tri-0-benzoyl-D-ribitol (54) also accessible from phenyl 2,3,5-tri-0-benzoyl-1 -thio-D-ribofuranoside (55).189... 

The isocyanide method of reduction has been applied successfully for preparing a series of diversely protected 1,4-anhydroalditols 188 l,4-anhydro-5-O-tert-butyldimethylsilyl-2,3-0-isopropylidene-D-ribitol (56, 81%), l,4-anhydro-5-0-terf-butyldimethylsilyl-6-deoxy-2,3-0-isopropylidene-D-allitol (57,87%) and -l-talitol (58,87%), 1,4-anhydro-2- 0-rert-butyldimethylsilyl-3,5- 0 -isopropylidene-... 

Peracetylated 1,5-anhydro-D-glucitol (41), -D-mannitol (42), -D-galactitol (43), -D-xylitol (44), -D-ribitol (65), and 2,3,5-tri-0-acetyl-1,4-anhydro-D-ribitol (66) were prepared in high yield from the corresponding glycosyl bromides on treatment with titanocene boiohydride (CpzTiBHO.193 The reaction also proceeded with... 

Acid hydrolysis of cytidine ribitol pyrophosphate led to a series of products, depending on the conditions of hydrolysis. L-Ribitol 1-phosphate (n-ribitol 5-phosphate), isomeric ribitol phosphates formed by acid-catalyzed migration of the phosphate group from the terminal position, and 1,4-anhydro-DL-ribitol were isolated. 

Varela and Zunszain [18] synthesized 4-thio analogs 16 of D-ribonolactone as well as L-lyxonolactone (Figure 9.5). Approaches to l,4-anhydro-4-thio-D-17 and -L-ribitol were recently described by Altenbach and coworkers [19,20]. l,4-Anhydro-4-thio-D-arabinitol was employed in the synthesis of a potential inhibitor of glycosyl transferases [21]. Access to 4-thiopentonolactones has also been provided, for example, by Dominguez and Owen [22]. 

A universal support for oligonucleotide synthesis has been described (136). The support was synthesised from 1,4-anhydro-D-ribitol. ... 

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