α-D(+)-glucose and β-D - (+) -glucose are

Concept:

• Epimers:

  • Epimers are stereoisomers that differ in configuration at only one specific carbon atom.

  • They are a subtype of diastereomers.

  • An example is D-glucose and D-mannose, which differ only at C-2.

• Conformers:

  • Conformers are different spatial orientations of the same molecule, usually due to rotation around single bonds.

  • They interconvert easily and do not have a distinct difference in connectivity or configuration.

  • An example is different chair forms of cyclohexane.

• Enantiomers:

  • Enantiomers are a pair of molecules that are non-superimposable mirror images of each other.

  • They have opposite configurations at all chiral centers.

  • Example: D-glucose and L-glucose.

• Anomers:

  • Anomers are a type of epimer that differ in configuration specifically at the anomeric carbon, which is the carbon derived from the carbonyl carbon (C=O) in the open-chain form.

  • In glucose, this corresponds to the C-1 position.

  • α and β anomers interconvert in aqueous solution through mutarotation (e.g., α-D-glucose and β-D-glucose).

Explanation:

• α-D(+) - Glucose and β-D-(+) - Glucose:

  • These two forms differ only at the anomeric carbon (C-1 in glucose).

  • In the α form, the OH group on the anomeric carbon is on the opposite side (trans) of the ring relative to the CH₂OH group.

  • In the β form, the OH group on the anomeric carbon is on the same side (cis) of the ring relative to the CH₂OH group.

  • 

  • These are classic examples of anomers.

Conclusion:

α-D(+) - glucose and β-D-(+) - glucose are: Anomers