Molecular Sieves Mediated Green Per-O-Acetylation of Carbohydrate Templates and Lipase Catalyzed Regioselective Alcoholysis of 2,3,5-Tri-O-Acetyl-D-Ribonolactone

Journal of the Brazilian Chemical Society

Herbert M. Cardozo¹  Thaís F. Ribeiro¹  Marcus M. Sá¹  Damianni Sebrão¹  Maria G. Nascimento¹  Gustavo P. Silveira¹ 

关键词: D-ribonolactone;    per-O-acetylation;    regioselective alcoholysis;    CAL-B;    molecular sieves;   

DOI  :  10.5935/0103-5053.20150037

来源: SciELO

【 摘 要 】

The per-O-acetylation of D-ribono-1,4-lactone and representative carbohydrates through the combination of acetic anhydride and molecular sieves under solvent-free conditions is demonstrated. The use of 13X/KCl molecular sieves as the heterogeneous catalyst was found to be more efficient than the excess of pyridine normally employed in the conventional method, giving high yields of the expected peracetylated product after 3 h at 25 ºC or 1 h at 50 ºC. The transformation can be carried out in gram scale and in an open flask. Additionally, the catalyst is readily separated from the reaction medium and can be reutilized without significant loss of activity. This green procedure for acetylation was extended to D-ribonolactone derivatives and natural carbohydrates. To demonstrate the synthetic utility of the method, 2,3,5-tri-O-acetyl-D-ribonolactone was selected as the substrate for the regioselective alcoholysis of acetyl group catalyzed by Candida antarctica lipase B in EtOH to selectively produce 2,3-di-O-acetyl-D-ribonolactone in gram scale.

【 授权许可】

CC BY   
 All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License