JOURNAL OF CHEMICAL EDUCATION
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A MNEMONIC AID FOR ALDOSES' WILL 8. DELOACH AND ANN BRANDON Arkansas State Teachers College, Conway, Arkansas
IF THE D-aldoses (through the hexoses) are built down from n-glyceric aldehyde, there is formed a pyramid consisting of one triose, two tetroses, four pentoses, and eight hexoses. If, in each pair of compounds formed by adding one carbon atom to the one above it, the formula of the one with the OH group of the new asymmetric carhon atom on the left is written on the left and the other on its right, the names of the compounds will be in this order: Glyceric aldehyde Threose Erythrose Lyxope Xylose Arabinose Ribose Talose Galactose Idose Gulose Mannose Glucose Altrose Allose
The position of each compound in this table is related in a regular manner to the configurations of the asymmetric carbon atoms. For example, the comPresented at the Southeastern Regional Meeting of the American Chemical Societv. Birrnineham. Alabama. October. 1
pound a t the right end of each row has all of the OH groups on the right, and the compound a t the left end has all OH groups on the left, except the bottom one. The following can be used to help remember the order of the names: (1) Write GATE
GA T A
(2) Write LXAR L (This might be remembered as LIAR, with a stroke across the I to make it X . ) (3) Write TIM T I ( 4 ) Add a G after each of these G G (5) Add two A's a t the end
The complete form is then
-B
X A R dl
G AA
GA T
L X A TGIG MG
-7?!
R AA
If there is difficultyin remembering which A stands for altrose and which for allose, it might be noted that when the last letter is reached, "that's all" (allose).
