ZnI2-Mediated β-Galactosylation of C2-Ether-Type Donor

Org Lett. 2022 Nov 4;24(43):8025-8030. doi: 10.1021/acs.orglett.2c03256. Epub 2022 Oct 25.


Conventional glycosylation with galactosyl donors having C-2 benzyl (Bn) ether-type functionality often leads to anomeric mixtures, due to the anomeric and steric effects that stabilize the 1,2-cis-α- and 1,2-trans-β-glycosides, respectively. Herein we report a versatile ZnI2-directed β-galactosylation approach employing a 4,6-O-tethered and 2-O-Bn galactosyl donor for the stereoselective and efficient synthesis of β-O-galactosides. With a broad substrate scope, the reaction tolerates a wide range of functional groups and complex molecular architectures, providing stereocontrolled β-galactosides in moderate to excellent yields. The practicality of this transformation is demonstrated through the synthesis of a tetrasaccharide arabinogalactan fragment with high stereoselectivity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Ether*
  • Ethers
  • Ethyl Ethers
  • Galactosides
  • Glycosides* / chemistry
  • Glycosylation
  • Stereoisomerism


  • Ether
  • Glycosides
  • Ethers
  • Ethyl Ethers
  • Galactosides