Allyl 4,6-O-benzylidene-2-deoxy-2-phtalimido-1-β-D-galactopyranoside

Allyl 4,6-O-benzylidene-2-deoxy-2-phthalimido-1-β-D-galactopyranoside

Allyl 4,6-O-benzylidene-2-deoxy-2-phthalimido-1-β-D-galactopyranoside is a synthetic glycoside derivative designed for advanced carbohydrate chemistry applications. This compound integrates multiple protecting groups to enable controlled reactivity during oligosaccharide synthesis.

Chemical Structure

The molecule is based on a β-D-galactopyranoside scaffold with the following modifications:

• 1-Allyl group: An allyl group at the anomeric position, forming a glycosidic linkage that enhances stability and serves as a glycosyl donor in synthetic reactions.
• 4,6-O-benzylidene group: A benzylidene acetal protection spanning positions 4 and 6, providing stability under acidic conditions and enabling selective deprotection later.
• 2-Deoxy-2-phthalimido group: A 2-amino sugar derivative protected by a phthalimido group, which is acid-stable and removable via mild hydrolysis (e.g., hydrazine).

Key Properties

• Molecular formula: Estimated to be C23H25NO6\text{C}_{23}\text{H}_{25}\text{NO}_6C23H25NO6 based on analogous structures.
• Stereochemistry: β-configuration at the anomeric center (C1), critical for mimicking biological glycosylation patterns.
• Role in synthesis:
  • The allyl group facilitates activation for glycosylation reactions.
  • Benzylidene group ensures regioselective reactivity, while phthalimido protects the amino group during glycosylation steps.

Applications

This compound is used in solid-phase oligosaccharide synthesis to build complex glycans. Its design supports iterative coupling cycles, where the benzylidene group can be selectively removed to expose the 4-OH and 6-OH for subsequent glycosylation. The phthalimido group remains intact during these steps, enabling late-stage functionalization of the amino group.

Synthetic Considerations

• Preparation: Likely synthesized via sequential protection:
  1. Phthalimidation of galactose at position 2.
  2. Benzylidene protection at positions 4 and 6.
  3. Allylation at the anomeric position.
• Stability: Stable under standard glycosylation conditions but sensitive to conditions that cleave the benzylidene group.

This multifunctional building block exemplifies advanced strategies in glycochemistry, balancing stability and orthogonality for automated glycan assembly.

Citations:

1. https://pubs.rsc.org/en/content/getauthorversionpdf/c9ob01610d
2. https://pubmed.ncbi.nlm.nih.gov/1394300/
3. https://pubs.acs.org/doi/10.1021/jo00296a055
4. https://patents.google.com/patent/US20040019198A1/en
5. https://pmc.ncbi.nlm.nih.gov/articles/PMC6474417/