Catalytic properties of microporous zeolites in the synthesis of octyl glucoside from D-glucose with 1-octanol by single-step direct glucosidation

• The octyl glucosides could be synthesized conveniently by single-step direct glucosidation.
• The zeolite catalysts exhibited high catalytic activities in this work.
• The conversion and yield were improved with increasing the amount of acid sites of the zeolite catalysts.
• H-FAU(3) catalysts exhibited the highest OGP selectivity among the catalysts.
• The OGPs show a significantly low estrogen cell proliferation compared with 17β-estradiol and nonylphenol.

Catalytic properties of various microporous zeolites consisted of different acidic properties and pore topologies were studied in the synthesis of octyl glucoside from D-glucose with 1-octanol by single-step direct glucosidation. The influences of acidic properties and pore topologies of the zeolite catalysts were evaluated relating to the conversion of glucose and selectivities of octyl glucosides. The octyl glucosides could be synthesized conveniently by the single-step direct glucosidation through aging of reactants without further pre-treatment or additional supply of reactant. The reusability of the zeolite catalyst was evaluated to the used zeolite. The high conversion of D-glucose was obtained on H+ ion exchanged FAU (H-FAU) zeolite which has a mild acid strength. The conversion and yield were improved with increasing of acid site amount of the zeolite catalysts. H-FAU zeolite catalysts exhibited high octyl glucopyranoside selectivity owing to relatively a large pore cavity and a high concentration of mild acid sites. The selectivities of the octyl glucoside isomers were mainly depended on the differences of pore structure and concentration of acid sites of the zeolite catalysts. The zeolite used in the reaction was able to reuse through the regeneration process.

The main products in the reaction were the anomeric mixture of two octyl glucosides i.e. (α,β)-octyl glucopyranoside and (α,β)-octyl glucofuanoside isomers. The reaction path of the direct glucosidation of D-glucose with 1-octanol is depicted in figure. It has been known that glucofuranoside appears as a primary and unstable product while glucopyranoside corresponds to a secondary and stable product.Figure optionsDownload as PowerPoint slide