Streamlined access to carbohydrate building blocks: Methyl 2,4,6-tri-O-benzyl-α-d-glucopyranoside

Abstract

Presented herein is an improved synthesis of a common 3-OH glycosyl acceptor. This compound is a building block that is routinely synthesized by many research groups to be used in glycosylation refinement studies. The only known direct synthesis by Koto lacks regioselectivity and relies on chromatography separation using hazardous solvents. Our improved synthetic approach relies on Koto's selective benzylation protocol, but it is followed by acylation-purification-deacylation sequence. Although this approach involves additional manipulations, it provides consistent results and is superior to other indirect strategies. Also obtained, albeit in minor quantities, is 4-OH acceptor, another common building block.

Keywords: Benzylation; Regioselectivity; Synthesis.