Crystal structure of β-d,l-fructose

Area of Science:

• Carbohydrate Chemistry
• Crystallography
• Structural Biology

Background:

• Fructose (C6H12O6) exists in various isomeric forms, including pyranose and furanose rings.
• Understanding the crystalline structure of fructose isomers is crucial for predicting their physical and chemical properties.

Purpose of the Study:

• To determine the crystalline structure of fructose formed from an equimolar mixture of d- and l-fructose.
• To elucidate the specific conformation and intermolecular interactions within the fructose crystal.

Main Methods:

• Crystallization of fructose from an aqueous solution.
• X-ray diffraction analysis to determine the crystal structure.

Main Results:

• Confirmation that d-fructose and l-fructose form a β-pyranose structure with specific (2)C5 and (5)C2 conformations, respectively.
• Identification of O-H⋯O hydrogen bonds connecting homochiral molecules into columns along the a-axis.
• Observation of inter-column hydrogen bonding between d- and l-fructose molecules, forming a 3D network.

Conclusions:

• The study provides detailed structural insights into crystalline fructose, highlighting the role of hydrogen bonding in network formation.
• The findings contribute to the understanding of monosaccharide stereochemistry and intermolecular forces in the solid state.