A Simple Synthesis Route for Selectively Methylated β-Cyclodextrin Using a Copper Complex Sandwich Protecting Strategy

Abstract

This communication reports a novel synthesis route for the preparation of monofunctionalized β-cyclodextrin in a single stage. The approach involves only the in-situ protection of secondary hydroxyl groups as an excellent alternative to the classical procedure involving a series of five steps of protection and deprotection of hydroxyl groups (both primary and secondary ones) belonging to β-cyclodextrin.

Synthesis and Inclusion Properties of a β-Cyclodextrin Heptaphosphoramidate

“…Chemical modifications have been carried out on β-CD in order to improve the inclusion and water solubilities of β-CD derivatives [ 15 ]. The three most successful strategies—O-(2-hydroxy)propylation, O-methylation, and O-(4-sulfo)butylation ( Figure 1 )—yield 2-hydroxypropyl-β-CD [ 16 , 17 , 18 ] (HPBCD, 1 ), randomly substituted methyl β-CD [ 19 , 20 ] (RMBCD, 2 ) and sulfobutyl ether β-CD [ 21 , 22 , 23 , 24 ] (SBEBCD, 3 ,) respectively, which have become the top three major chemically modified β-CDs in the commercial markets worldwide. The CD derivatives offer enhanced water solubility and low toxicity.…”