Ethyl 4,6-O-benzylidene-1-thio-β-D-glucopyranoside

Ethyl 4,6-O-benzylidene-1-thio-β-D-glucopyranoside

Ethyl 4,6-O-benzylidene-1-thio-β-D-glucopyranoside is a carbohydrate derivative widely used in synthetic organic chemistry, particularly in glycosylation reactions. This compound belongs to the class of thioglycosides, where the anomeric oxygen of a sugar is replaced by a sulfur atom, enhancing its stability and utility as a glycosyl donor.

Chemical Identity

• CAS Number: 20701-61-5
• Molecular Formula: C₁₅H₂₀O₅S
• Molecular Weight: 312.38 g/mol
• Synonyms: Includes ethyl 4,6-O-benzylidene-b-D-thioglucopyranoside and β-D-glucopyranoside derivatives.

Molecular Structure and Conformation

The molecule features a benzylidene group protecting the 4,6-hydroxyl positions of the glucopyranoside ring, leaving the 2- and 3-hydroxyl groups available for further modifications. Key structural insights from related derivatives include:

• The thioethyl group adopts an exo-anomeric conformation, minimizing steric hindrance and stabilizing the molecule.
• Intermolecular hydrogen bonds involving hydroxyl groups and carbonyl oxygens contribute to crystalline packing, forming chains stabilized by C–H⋯π interactions.

Synthesis and Applications

This compound serves as a critical intermediate in glycoside synthesis:

• Glycosylation Reactions: Used in TMSOTf-mediated condensations with trichloroacetimidate donors to construct complex oligosaccharides. For example, it was employed in the synthesis of verbascoside, a bioactive phenylethanoid glycoside.
• Protection Strategy: The benzylidene group acts as a temporary protecting group, enabling selective functionalization of the glucopyranoside ring.

Physical Properties

• Crystalline Behavior: Forms hydrogen-bonded chains in the solid state, as observed in structurally similar derivatives.
• Reactivity: The thioethyl group enhances stability while allowing activation under mild conditions for glycosidic bond formation.

This compound’s versatility in synthetic pathways and structural stability makes it indispensable in carbohydrate chemistry, particularly for synthesizing bioactive natural products.

Citations:

1. https://www.chemicalbook.com/ChemicalProductProperty_EN_CB0958527
2. https://www.chemicalbook.com/ChemicalProductProperty_US_CB8958442.aspx
3. https://pmc.ncbi.nlm.nih.gov/articles/PMC3011798/
4. https://www.lookchem.com/casno61276-17-3.html