Novel Selectivity in Carbohydrate Reactions, IV: DABCO-Mediated Regioselective Primary Hydroxyl Protection of Carbohydrates

Abstract

An efficient procedure for the regioselective tritylation of primary hydroxyl group of aldohexopyranosides and nucleosides using trityl chloride in the presence of 1,4-diazabicyclo[2.2.2]octane (DABCO) in dichloromethane has been developed. Subsequent acetylation of the tritylated products in the same pot has been made possible, thereby providing an efficient route to the fully protected carbohydrate derivatives that can be discriminated chemoselectively.

Keywords:

• DABCO-mediated alkylations
• pyridine/DMF-free tritylation
• regioselective tritylation

ACKNOWLEDGMENTS

B. K. Ghadakh and P. R. Patil thank NIPER, and S. Malik and K. P. R. Kartha thank the University Grants Commission, New Delhi, India, and the Department of Science and Technology, New Delhi, India, respectively, for providing financial support.

Notes

^a All reactions were carried out using 1 mmol of glucoside 1 in CH₂Cl₂ (4 mL) at rt.

^a All reactions were performed using 1 mmol of the glucoside 1 in the respective solvent (4 ml) at rt.