Z. I. Glebova

Shortest route to 2-deoxyaldonic acids

In the present work we suggest such a procedure that involves 1-C-nitromethylpolyols as potential sources of carbonyl-containing carbohydrate derivatives. Previously we reported a one-pot synthesis of the base nitro derivative III [1]. The universality of this new methods of reductive nitromethylation of aldoses like I and II we confirmed by the synthesis of dicyclohexylidene-D-arabino-hexitol (IV) in a yield of 62%.

Transformation of Acetalized Polyhyroxyketene Thioacetal in Acid-Alcohol Medium

Abstract2,3:4,5-Di-O-cyclohexylidene-L-arabinose diethyl dithioacetal was treated with sodium methylsulfinylmethylide to prepare a novel compound, 4,5-cyclohexylidene-2-deoxy-L-erythro-pent-1-enose diethyl dithioacetal. The product undergoes a series of transformations in anhydrous ethanol in the presence of p-toluenesulfonic acid: alcoholysis of the cyclohexylidene protection, elimination of water, migration of the double bond, formation of an acyclic allyl cation, elimination of the ethylthio group, formation of a cyclic allyl cation, migration of the mercapto group from C1 to C3,addition of alcohol, and formation of an acetalized lactone. The latter was acetalized to obtain a diastereomeric mixture of 5-O-acetyl-2-deoxy-3-S-ethyl-L-threo- and -erythro-pentono-1,4-lactones.

Application of the System Dimethyl Sulfoxide-Acetic Acid Anhydride in the Oxidation of Carbohydrate α-Hydroxyphosphonates.

The α-phosphorylated L-xylose (I) is oxidized by dimethyl sulfoxide/ acetic anhydride to give the isomeric enolates E- and Z-(III).

RK. VON ALPHA-HALOGENKETOSEN MIT TRIAETHYLPHOSPHIT

1-Chlor-1-desoxy-3,4,5,6,7-penta-O-acetyl-D-galaktoheptulose (Ia) und 1-Brom- 1-desoxy-3,4,5,6-tetra-O-acetyl-L-fructose (Ib) reagieren in siedendem Benzol mit Triathylphosphit (II) mit Ausbeuten um 35% zu den in 1-Stellung durch den Zuckerrest substituierten Diathylvinylphosphaten (IIIa) und (IIIb).