Stereoselective Synthesis of α‐ʟ‐Rhamnopyranosides from ʟ‐Rhamnal Employing Ruthenium‐Catalysis.

An alternative and highly efficient ʟ‐rhamnosylation highlighting the dual‐catalysis of ruthenium reagent under a stereocontrolled process has been realized. The Ru‐mediated direct glycosylation‐dihydroxylation from ʟ‐rhamnal is amenable to a wide range of acceptors, including sugars, amino acids, natural products, and bioactive scaffolds. The one‐pot protocol tolerating diverse functional groups is attractive due to the valuable synthetic utility in assembling biologically significant α‐ʟ‐rhamnopyranosides in good yields. The mechanistic rationalization for the α‐anomeric selectivity and syn‐diastereoselective dihydroxylation employing Ru‐catalysis has been presented. [ABSTRACT FROM AUTHOR]