Altrose from Ribose

In the synthesis of n-altrose from D-ribose, first effected by Levene and Jacobs, the only crystalline intermediate was the characteristic calcium D-altronate -3.5 H2O. The sirupy lactone prepared from it was then reduced to n-altrose with sodium amalgam, as mentioned earlier in this review. Calcium n-altronate has been obtained from other sources also, such as the aluminum chloride rearrangement of the acetates of lactose, cellobiose and glucose and subsequent transformation of the neolactose, celtrobiose and altrose derivatives thus produced (see Section... 

Preparation. L-Altrose can be prepared by the Kiliani synthesis, starting from L-ribose.79 More recently, an efficient synthesis of L-altrose starting from glucose has been reported.80... 

The structural assignment for the four sugars obtained from o-ribose and D-lyxose, respectively, is again accomplished by oxidation to the corresponding aldaric acids. Both D-aUose and D-galactose give optically inactive oxidation products, in contrast with o-altrose and D-talose, which give optically active dicarboxyUc acids. 

Because two products form, we still need information from other reactions to establish the structure of each. For example, ribose gives two structures whose configuration at all centers except C-2 is known. One product is oxidized to give an optically inactive glycaric acid. It must be aUose. The other product must therefore then be altrose. If altrose is oxidized, the product is an optically active aldaric acid. 

In this manner 3-amino-3-deoxy-D- and -L-ribose, 3-amino-3-deoxy-D-mannose and 3-amino-3-deoxy-D-glucose have been prepared. In an analogous way Richardson and Fischer , starting from laevoglucosan, obtained 3-amino-i,6-anhydro-3-deoxy-D-glucose, -D-altrose and -D-idose. 

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