Ketoses diazomethane synthesis

The action of diazomethane converts acetylated aldonyl chlorides into 1-diazoketose derivatives having one additional carbon atom in the carbon chain the diazo group may be replaced by different nucleophiles. This versatile synthesis of ketoses has been widely applied by Wolfrom and Thompson.94... 

This method for the synthesis of higher-carbon ketoses is based on the reaction of diazomethane with an acid chloride to give a diazomethyl ketone which, on hydrolysis (or acetolysis), furnishes a hydroxy (or acetoxy) methyl ketone. The reaction was first applied in the sugar field in 1938 and has since been widely used in the synthesis of ketoses by Wolfrom and coworkers. As developed by Wolfrom, the synthesis uses fully acety-lated derivatives in the following stages aldose — acetylated aldonic acid acetylated aldonyl chloride acetylated diazomethyl ketose — acetylated ketose — ketose. The method is illustrated in the synthesis of D-galacto-heptulose (10). ... 

The Action of Diazomethane upon Acyclic Sugar Derivatives. III. A New Synthesis of Ketoses and of their Open Chain (keto) Acetates, M. L. Wolfrom, S. W. Waisbrot, and Robert L. Brown, /. Amer. Chem. Soc., 64, 2329-2331 (1942). 

The action of diazomethane on an acid chloride to give a diazomethyl ketone 155) and the hydrolysis or acetolysis of the latter is applicable as a method of synthesis for higher-carbon ketoses 156a-d). 

As noted above, the ketoses are especially prone to produce acyclic acetates by methods of direct acetylation, as exemplified by D-fructose 1) and D-sorbose 23). It has been demonstrated by Pacsu 1) and by Wolfrom and Thompson 1) that the long known penta-0-acetyl- a -D-fructose of Hudson and Brauns 1) has a free ketonic group. A general method, involving the action of diazomethane on 0-acetylated aldonic acid chlorides, has been developed for the synthesis of 0-acetyl-fceZo-sugars 24) (see formulas). 

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