Synthesis of alpha-Gal C-disaccharides

Area of Science:

• Carbohydrate Chemistry
• Organic Synthesis
• Glycoscience

Background:

• α-Gal glycans are crucial in biological processes.
• Understanding α-Gal glycan biology requires specific molecular tools.
• Previous synthetic routes for α-Gal C-disaccharides were limited.

Purpose of the Study:

• To develop a versatile synthetic strategy for C-disaccharides of α-D-galactopyranosyl-(1->3)-D-galactopyranose (α-Gal).
• To create potential tools for studying the biological roles of α-Gal glycans.
• To enable the synthesis of diverse α-Gal glycoconjugates.

Main Methods:

• Utilized a synthetic strategy involving 1,2-O-isopropylidene-d-glyceraldehyde and an α-C-galactosyl-E-crotylboronate precursor.
• Employed (R)- and (S)-TRIP catalysts to control the stereoselectivity of the anti-crotylation reaction.
• Transformed the desired diastereomer into C-linked α-Gal disaccharides with various aglycone linkages (O-, C-, and S-glycosides).

Main Results:

• Successfully synthesized C-disaccharides of α-D-galactopyranosyl-(1->3)-D-galactopyranose (α-Gal).
• Achieved stereoselective control over the key crotylation step using TRIP catalysts.
• Generated α-Gal C-disaccharides featuring O-, C-, and S-glycoside aglycones, suitable for further glycoconjugate synthesis.

Conclusions:

• A robust synthetic route for α-Gal C-disaccharides has been established.
• The developed methodology provides valuable tools for α-Gal glycan research.
• The synthesized compounds facilitate the construction of complex glycoconjugates for biological studies.