Hexoses: Difference between revisions

The applet on the right shows D-fructose in a conformation in which the oxygen of C-5 is in position to react with C-2, the carbonyl carbon, forming a hemiketal<ref>[http://en.wikipedia.org/wiki/Hemiacetal Hemiketal]</ref>. As in the case of glucose forming a hemiacetal, the carbonyl carbon becomes a chiral carbon and an anomeric carbon. The two possible anomers are called α-D-fructofuranose<ref>[http://en.wikipedia.org/wiki/Furanose Furanose]</ref> and β-D fructofuranose. The α and β furanoses are shown below.

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<Structure load='Alpha fructose.pdb' size='400' frame='true' align='left' caption='' scene='Hexoses/Alpha_fructose/3' />

The α anomer on the left is shown with an edge-on-view, with the anomeric carbon (C-2) on the right side of the structure and with its hydroxyl group projecting down. C-1 is not part of the five membered ring and projects above the ring.  Toggle off the spin of the β anomer on the right and rotate the structure so that it has a position similar to that of the α anomer. Confirm that the configuration about the anomeric carbon of the β anomer is different from that of the α anomer.

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== Terms Defined in Wikipedia ==

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