Mannose has the same molecular formula as glucose and the same geometry except at carbon-2, where the \(\mathrm{H}\) and \(\mathrm{OH}\) groups are interchanged. Draw the structures of \(\alpha\) - and \(\beta\) -mannose.

Question: Draw the structures of α-mannose and β-mannose and explain the differences between them. Answer: α-mannose and β-mannose are isomers that have the same molecular formula (\(\mathrm{C_6H_{12}O_6}\)) but differ in the orientation of the hydroxyl group at the anomeric carbon (carbon-1). In α-mannose, the hydroxyl group at carbon-1 is axial (downwards) while in β-mannose, the hydroxyl group is equatorial (upwards). Besides this difference at the anomeric carbon, mannose also differs from glucose at carbon-2, where the \(\mathrm{H}\) and \(\mathrm{OH}\) groups are interchanged. The remaining functional group placements on carbons 3, 4, 5, and 6 are the same for both α-mannose and β-mannose.