Stereoselective Synthesis of β-Rhamnopyranosides via Gold(I)-Catalyzed Glycosylation with 2-Alkynyl-4-nitro-benzoate Donors

Stereoselective β-rhamnopyranosylation remains a challenge, due to the unfavorable anomeric effect and steric hindrance of the C2-substituent; herein, this challenge is addressed with a gold(I)-catalyzed SN2-like glycosylation protocol employing α-rhamnopyranosyl 2-alkynyl-4-nitro-benzoates as donors.