Allose Fischer projection

Once the eight Fischer projections have been written they are named m order with the aid of the sentence All altruists gladly make gum m gallon tanks The words of the sentence stand for allose altrose glucose mannose gulose idose galactose talose... 

The aldohexoses are allose, altrose, glucose, mannose, gulose, idose, galactose, and talose. The mnemonic All altruists gladly make gum in gallon tanks is helpful in writing the conect Fischer projection for each one. 

The other aldohexose that gives an optically inactive aldaric acid is D-allose, with all OH groups on the right side of the Fischer projection. Ruff degradation followed by nitric acid gives an optically inactive aldaric acid, however, so X cannot be D-allose. 

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