Representations of Sugars

Sugars are commonly represented with Fischer projections and Haworth projections. Review your class notes to see how to draw and interpret them.

In this course, we will limit our discussion to hexoses (sugars with 6 carbons). When these compounds form rings, the cyclic form is known as a pyranose. The beta anomer of D-glucose would be named as $$\beta$$-D-glucopyranose.

Some things to know about sugar structures:

• D- sugars will have the the C5 hydroxyl group on the right-hand side of the Fischer projection

• L- sugars are enantiomers of D- sugars. To identify L- sugars, draw the D- enantiomer and use Table 16.1 (provided on exam) to find the name.

• When drawing the Haworth from a Fischer, the groups on the left go up and groups on the right go down (be able to go from Haworth to Fischer). To identify sugars from Haworth projection, draw the Fischer and determine the name from Table 16.1 (provided on the exam).

• In the $$\beta$$ anomer, the methylene hydroxyl ($$-CH2OH$$) group will be _cis with the hydroxyl on the anomeric carbon

• In the $$\alpha$$ anomer, the methylene hydroxyl ($$-CH2OH$$) group will be _trans with the hydroxyl on the anomeric carbon

Practice converting back-and-forth between chairs, Haworth, and Fischer projections. Have fun! :)