The Pyranoses

In general a pyranose is any cyclic isomer that has a five carbons and one oxygen in a ring of six atoms. If a hydroxyl at the 5 position of an aldohexose, such as glucose, forms a hemiacetal with the aldehyde (position 1), the resulting isomer is glucopyranose. The hydroxyl group at position 1 is sterically undefined.

D-glucose as its pyranose and aldose forms

A pyranose structure with an undefined asymmetric center at position 1 represents both the α diastereomer and the β diastereomer. These two diastereomers have an indentical saccharide name, i.e. glucopyranose. The other hydroxyls at positions 2, 3, and 4, if changed, will result in a diastereomer with a different name. Pyranose monosaccharides are quite common in the literature—their conformation resembles the well-known cyclohexane system.

When there is more than one name for a pyranose, the name most often used in on top. Also where noted are other facts about the monosaccharide.

Pyranose Forms of the Hexoses

D-allose D-altrose D-galactose D-glucose
 
 
D-gulose D-idose D-mannose D-talose

Anhydro Sugars

2,3-anydro-α-Dallopyranose 1,6-anhydro-β-Dglucopyranose

Deoxy Sugars

D-arabinose
 
abequose
3,6-dideoxy-D-xylo-hexopyranose
fucose
6-deoxy-L-galactopyranose
D-lyxose
 
 
 
mycarose
(of carbomycin)
quinovose
6-deoxy-D-glucopyranose
rhamnose
6-deoxy-L-mannopyranose
D-ribose
 
 
 
  
paratose
3,6-dideoxy-D-ribohexopyranose
D-xylose
 
  

Heteroatom-Substituted Sugars

D-galactosamine
2-amino-2-deoxy-α/β-D-galactopyranose
D-glucopyranosylamine
 
 
 
 
D-glucosamine
2-amino-2-deoxy-α/β-D-glucopyranose
 

Others

glucal
 
vancosamine
(of vancomycin)

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