Alditols VOLUME

An article on the anhydrides of polyhydric alcohols appeared in Volume 5 of this Series,1 and it is the purpose of the present article to bring the subject up to date. Wiggins article1 was limited to the anhydrides of the pentitols and hexitols the present article will include the anhydrides of tetritols and of alditols higher than the hexitols. However, anhydrides having the three-membered (oxirane) ring will not be considered, as they are discussed elsewhere in this Volume.13 2,5-Anhydrides of aldoses are also treated in this Volume.lb... 

In view of this, a new overview of developments in this area is warranted, especially as no special summary on this subject has been published for some time. A comprehensive article2 in a previous volume of this series appeared in 1950. Subsequently, a brief discussion of 1,4 3,6-dianhydrohexitols was incorporated in a contribution on the stereochemistry of cyclic derivatives of carbohydrates,3 and they were treated exhaustively within a summary of alditol anhydrides that contained tables of physical properties of derivatives.4... 

Alditols [405] and amino sugars [406] have been analysed by GC—MS as combined methyl ether—acetyl derivatives. Acetylation was performed with acetic anhydride in pyridine, as follows. A 0.15-ml volume of re-distilled dry pyridine was added to 0.5 ml of 1.5 A acidic methanolysate containing 0.025—2.5 pmol of amino sugars. The apparent pH of the methanolic pyridinium hydrochloride varied in the range 4—5. Acetic anhydride (0.1 ml) was added and the mixture was stirred thoroughly and allowed to stand at room temperature for 30 min. Evaporation to dryness was performed in vacuum over solid KOH with subsequent vacuum drying for 4 h over P20s. SE-30 was used as the stationary phase. 

Retention Volumes of Fully Acetylated Alditols Relative to Penta-O-acetyl-L-arabinitol at SIS"... 

Gas-Liquid Chromatography.—Phthalic esters - which are extensively used as plasticizers in the formulation of plastics used to make containers for solvents, etc. - have been found as contaminants during the analysis of polysaccharides by gas chromatography of the alditol acetate derivatives for example, dibutyl phthalate behaves as a tetritol tetra-acetate on g.l.c. and di(2-ethylhexyl) phthalate has a retention time close to that for xylitol penta-acetate. The contamination by phthalic esters can be minimized by distilling all solvents used in the analytical steps or by using smaller volumes of potentially contaminated solvents. 

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