Alditols dideoxy-, preparation

In addition to these physical studies at the Bureau, Tipson was able to return to his synthetic interests, both alone and in collaboration with other staff members. He was especially pleased to prepare D-talose in crystalline form, an accomplishment that had eluded Emil Fischer. Pursuing his longstanding interest in the reaction of sulfonic esters with iodide and following an earlier observation that the tetratosyl ester of erythritol is converted into butadiene by the action of sodium iodide and zinc, he demonstrated (with A. Cohen) that nonterminal unsaturation may be conveniently introduced into alditol derivatives by reaction of contiguous secondary sulfonates with sodium iodide and zinc dust in boiling A.A-dimethylformamide. This Tipson-Cohen reaction subsequently proved of great utility in other hands for the conversion of more complex carbohydrate structures into vicinal dideoxy derivatives. 

Lithium chloride, preferably dissolved in absolute ethanol, has also been used306 419 420 for preparing alkyl chlorides. Dissolved in absolute ethanol-acetone (1 1, by vol.), it has recently414 found application with alditol sulfonates. Its action on l,4 3,6-dianhydro-2,5-di-0-mesyl-L-iditol, l,4 3,6-dianhydro-2,5-di-0-mesyl-D-mannitol, and l,4 3,6-dian-hydro-2,5-di-0-mesyl- (and -2,5-di-O-tosyl-) sorbitol resembles the action of sodium iodide on these compounds, i.e., the first displays no appreciable reaction, the second gives the 2,5-dichloro-2,5-dideoxy derivative, and the last two afford the respective monochloromonodeoxy-mono-O-sulfonyl derivatives. Treatment of l,4 3,6-dianhydro-2,5-di-0-mesyl-sorbitol during 48 hours at 180-90° gives some of a dianhydro-mono-chloromonodeoxy-sorbitoleen. 

Attempts to use 4,5,7-tri-0-acetyl-2,6-anhydro-l,3-dideoxy-l-iodo-D-giuco-heptitol for x-ray analysis were unsuccessful, because only twinned crystals could be prepared. Use of die deacetylated p-toluenesulfonate, namely, 2,6-anhydro-3-deoxy-l-0-p-tolylsulfonyl-D-gl co-heptitol, and of the parent alditol, 2,6-anhydro-3-deoxy-D-glaco-hepti-tol, was unsuccessful because no atom of sufficient electron density was present. 

Anhydro Alditols. - A standard procedure has been used to convert the glucosamine derivative (13) to its 1,2-dideoxy analogue, and then to prepare the glycoprotein 1-deoxy-MDP and some other lipo-... 

A preparation of l,5-dideoxy-l,S-imino-D-allitol from A protected deoxynqjirimycin v ch involves a microbial redox reaction at C-3 has been described, and the glycosidase inhibitory properties of the product were determined together with those of other imino-alditols isolated from the leaves of Mens alba (see also ref 40 above). ... 

Amino-Alditols. - Aldose oximes, e.p... of mannose and arabinose, can be reduced electrochemically to 1-aminoalditols glucose oxime reacted differently, because, it is proposed, of its strong tendency to cyclize to an N-glucosyl hydroxylamine derivative. l-Amino-2-acetamido-1,2-dideoxy-D-alditols have been prepared by sodium cyano-borohydride reduction of 2-acetamido-2-deoxy-glycosylamines (D-Glc, D-Man, and D- lc-D-Glc).6-(5-deoxy-D-ribit-5-yl)amino-uracil has been condensed with 2-chloro-4-hydroxybenzaldehyde to give a flavin derivative which was further elaborated to Redox Coenzyme Factor 420. ... 

A combined enzymatic/chemical synthesis of imino-alditols used fructose 1,6-diphosphate aldolase to generate 6-azido-ketohexoses (as outlined in Scheme 4) which could be catalytically reduced to deoxynojirimycin and deoxymannojirimycin. By use of appropriate azido-aldehydes, fagomine(15) and 1,4-dideoxy-l,4-imino-D-arabinitol (16) were similarly prepared. Microbial epimerization of 1-deoxy-... 

Anhvdro-Alditols. - The synthesis of a whole range of 1,5- and 1,4-anhydro-alditols and their inhibitory effects against glycosidases have been reported. The preparation of 2,5-anhydro-3-deoxy-D-araWno-hexitol by hydrogenation of 2,5 3,4-dianhydro-D-allitol over Pearlman s catalyst has been described. The selective chlorination of pentitols to afford l,5-dichloro-l,5-dideoxy derivatives as well as mono- and di-chloro-l,4-anhydro derivatives has been reported. ... 

Deoxynojirimycin has been used as starting material for the preparation of a range of V-acetylamino-l,5-dideoxy-l,5-imino alditols. Thus the former was converted... 

Full details on the preparation of urethane derivatives of 3,4-di-O-benzyl-l,2,5,6-tetradeoxy-l,2 5,6-diimino-L-iditol from D-mannitol as well as the 3,4-dideoxy-L- Areo compounds 24 (R = C02 Bu or COiBn), from a hex-3-enitol, have been reported. (See Vol. 28, p. 230, ref. 66 for an earlier report). In both cases l,6-diamino-l,6-dideoxy-2,5-anhydroalditols were minor by-products. V-Boc-L-/V/o-l,2 5,6-bis-aziridino derivatives have proved to be versatile intermediates for the preparation of imino-alditols. For example, treatment of the 3,4-di-O-benzyl compound with diethylaluminium cyanide affords a 1 2 mixture of pyrrolidine 25 piperidine 26, and with dilithium tetrabromonickelate (Li2NiBr4) gives bromo-derivative 27 from which displacement of bromide allows further functionalization. ... 

Several imino-alditols have been prepared from non-carbohydrate sources. 2,S-Dideoxy-2,S-imino-D-mannitol has been synthesized from a pyroglutamic acid derivative (see Vol. 27, p. 209, ref. 59 for the use of pyroglutamic acid in the synthesis of other imino-alditols), and 1-deoxy-L-allonojirimycin has been made from a protected L-serine derivative. A protected D-serine aldehyde provided access to a l,2,4-trideoxy-l,4-imino-D-eryrAro-pentitol derivative for incorporation into DNA, and reduction of the minor natural amino acid, 4-L-hydroxyproline, gave l,3,4-trideoxy-l,4-imino-D-eryrAro-pentitol which, after Af-acylation with a fluorescent probe, was incorporated into oligonucleotides. ... 

The fucose-related imino alditol 249 has been prepared from 248, a series of l,5-dideoxy-l,5-iminoheptitols have been prepared from 2-bromoaldonolactones derived from D-glucose, D-mannose and D-galactose, n-Arabino- and D-gbico-... 

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