What is another name for an aldose that contains 6 carbons in its chemical formula?

1 Answer
Oct 14, 2015

A hexose, which is generically a sugar that had six carbons in its straight-chained form.


Simply put, "ose" is the suffix for a sugar, and "hex" is the prefix for six.

A hexose originally has 6 carbons as a straight-chained molecule, and after being put into water, it rapidly interconverts in an equilibrium between its straight-chained form and its cyclic form.

An aldose (sugar with an aldehyde group on one end) put into water forms a cyclic hemiacetal, heavily favoring its cyclic form usually.

When it forms a ring, it has 5 carbons in the ring, 1 oxygen in the ring, and 1 #"CH"_2"OH"# as a substituent on the ring (that's where the sixth carbon went; it's the terminal carbon).

For example, glucose does this mechanism in water due to water's autoionization to form the anomers #beta#-glucopyranose (top) and #alpha#-glucopyranose (bottom):

(The anomeric carbon is the carbon where the original aldehyde group was. The #alpha# means the anomeric carbon has an axial #OH#, and the #beta# means the #OH# is equatorial.)