A green procedure to perform the reaction between carbohydrate hydroxyls and epoxides.

What is it about?

Describes the reactions between liquid epoxides and cyclodextrin hydroxyls to prepare the most popular (2-hydroxy)propyl cyclodextrins and gives a simple and standardizable production of cyclodextrin polymers, particularly the insoluble cyclodextrin polymers. One-step preparation of (2-hydroxy)propyl cyclodextrins of high-degree of substitution demonstrated the flexibility and easy scalability of mechanochemical organic syntheses. Complexation properties of the synthesized cyclodextrin derivatives are also shown.

Featured Image

Why is it important?

Syntheses of the targeted derivatives are performed in aqueous solutions. To obtain a solid form of (2-hydroxy)propyl cyclodextrins requires the removal of water which is expensive by the high energy demand for water removal. The mechanochemical method results in a solid form of product and water could be substituted with a green organic solvent. The commercial availability of cyclodextrin polymers is limited and their preparation is poorly reproducible. The solvent-free, simple, and efficient synthesis of these cyclodextrin derivatives is solved by using a ball-mill. One run in a lab-scale planetary ball mill gives >30 g product in a 125 ml reaction jar. The prepared polymers have comparable complexation properties with the polymers of traditional synthesis.

Perspectives