Pentitols preparation

III. Synthesis of Pentitols from Unsaturated Intermediates 1. Methods of Preparation... 

Some other water-soluble fully sugar-based polyamides have also been obtained from activated hexaric acids 28 and 29 and the 1,5-diamino-2,3,4-tri-O-methyl-pentitols (37 and 38) and a series of hydrophilic polyamides (PA-nSu) derived from these hexaric acids and noncarbohydrate alkylenediamines with even numbers of methylenes n = 4, 6, 8, 10, 12) has also been prepared [80]. 

PREPARATION OF (R,R)-1,2 4,5-DIEPOXYPENTANE (D-threo-Pentitol, 1,2 4,5-dlanhydro-3-deoxy-)... 

LespiEau, R., Synthesis of Hexitols and Pentitols from Unsaturated Poly-hydric Alcohols, 2, 107-118 Levi, Irving, and Purves, Clifford B., The Structure and Configuration of Sucrose (ofplia-D-Glucopyranosyl beta-n-Fructofuranoside), 4, 1-35 Levvy, G. A., and Marsh, C. A., Preparation and Properties of 0-Glucuronidase, 14, 381-428 Levvy, G. A. See also, Conchie, J. Liggett, R. W., and Deitz, Victor R., Color and Turbidity of Sugar Products, 9, 247-284... 

Two years after the first preparation of L-ribose, Fischer74 described the reduction of the sugar with sodium amalgam to the corresponding pentitol, which he showed to be identical with the polyol adonitol from Adonis vernalis L.75 76 A process for the catalytic hydrogenation of D-ribose in the presence of magnesium-activated Raney nickel to ribitol has been patented.77... 

A series of thioanhydroaldoses and thioanhydropentitols, for example 50, has been prepared via the electrophilic bis-cyclic thionocarbonate 51, which was in turn obtained by treatment of the monobenzyl pentitol 52 with diimidazolyl thione (Im2CS) <04TL4365>. 

Attempts to prepare esterified glycals by the reduction of glycofuranosly halides with zinc in acetic acid failed, because of the reactivity of this class of compound (see p. 92). When, however, 3,5-di-0-benzoyl-2-0-(p-nitrophenylsulfonyl)-/3-D-ribofuranosyl bromide (8) in acetone is treated at 5° with sodium iodide, a facile elimination takes place and 3,5-di-O-benzoyl-1,2-dideoxy-D-er2/i/iro-pent-l-enofuranose (9) is obtained crystalline, in 72% yield. The product was characterized by identifying its hydrogenation product as the known l,4-anhydro-3,5-di-0-benzoyl-2-deoxy-D-er2/nuclear magnetic resonance spectrum, which showed clearly that the glycal structure was present. 

CjHijOj, Mr 152.15, water-soluble, sweet-tasting, colorless prisms, mp. 103 °C, [a]r, +8° (HjO) (D-forrn) or wart-like crystals, mp, 102 °C, [0] - 5° (H2O) (L-form). A. belongs to the group of pentitols or pentahydroxy alcohols and can be prepared by reduction of arabi-nose or lyxose. d-A. is frequently found in lichens and fungi. 

Biological dehydrogenation of 2-deoxy-D-erythro-pentitol (6) by Glucono-bacter oxydans has been used to prepare 4-deoxy-L-g /ycero-pentulose (7), characterized by m.s. of its tri(trimethylsilyl) derivative. ... 

Acyclic Derivatives - l,5-Diazido-l,5-dideoxy-D-pentitols are readily reduced to the corresponding l,5-amino-l,5-dideoxy derivatives. (See above for the preparation of the diazido compounds). ... 

Deoxy-5-seleno-D-arabino-, D-ribo- and D-xylo-selenoformates 8, 9 and 10 have been prepared from D-arabinose and known 2,3,4-tri-O-benzyl-D-ribose and -D-xylose diethyl dithioacetals, respectively/ The thermolysis of these compounds to afford l,5-anhydro-5-deoxy-5-seleno-D-pentitols is covered in Chapter 11. 

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