Heptose

A heptose is a monosaccharide with seven carbon atoms.

They have either an aldehyde functional group in position 1 (aldoheptoses) or a ketone functional group in position 2 (ketoheptoses).

There are few examples of C-7 sugars in nature, among which are:

Ketoheptoses have 4 chiral centers, whereas aldoheptoses have 5.