Lewis Acid-Mediated Domino Glycosylation/Cyclization of Substituted Glycals: A Stereoselective Route Toward the Synthesis of 1,2-Annulated C-Glycosides

Organic Letters, Journal Year: 2025, Volume and Issue: unknown

Published: March 14, 2025

Annulated C-glycosides are widely recognized for their natural abundance and diverse bioactivity. Traditional synthesis emphasizes stereoselective α/β C-glycoside formation, but efficiently engaging both reactive carbons of glycosyl donors remains challenging. This study introduces a novel domino sequence using substituted glycals β-naphthols under Lewis acid catalysis, generating glycosylated intermediates that undergo cascade reactions to yield annulated 1,2-C-glycosides. The method features broad substrate scope, mild conditions, versatility. Notably, annulation type varies with glycals, yielding [3 + 2] or 3] fused pyran systems. Control experiments DFT calculations provide mechanistic insights into substrate-specific product formation.

Language: Английский

Hydrogenation of Sugar Enol-Ethers Using Pd/Et₃SiH Reagent System: A Route to Deoxy Sugars/Glycosides

The Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: unknown

Published: Dec. 16, 2024

We have developed a hydrogenation method using Pd(OAc)2/Et3SiH as reagent system for sugar enol ethers and their glycosides. This approach is highly effective applicable to wide range of glycals glycosides, achieving yields up 96% the corresponding deoxy sugars. Applying standard conditions various O/C-glycosides resulted in excellent transformation 2,3-dideoxy

Language: Английский