Practical Synthesis of Oxepanoprolines

Area of Science:

• Organic Chemistry
• Medicinal Chemistry
• Synthetic Chemistry

Background:

• The oxepanoproline southern fragment is crucial for synthesizing antibiotic candidates such as iboxamycin, cresomycin, and BT-33.
• Existing synthetic routes may lack scalability or efficiency for producing these important fragments.

Purpose of the Study:

• To develop a more scalable and efficient synthetic route for the oxepanoproline southern fragment.
• To establish a method for assembling multiple stereocenters in a single operation.

Main Methods:

• A diastereoselective titanium tetrachloride (TiCl4)-mediated conjugate addition of an allylsilane to an Evans N-acryloyloxazolidinone.
• Subsequent syn-aldol addition of the resulting titanium enolate to (R)-Garner's aldehyde.

Main Results:

• The described route provides a scalable method for synthesizing the target oxepanoproline fragment.
• The key transformations efficiently assemble all necessary stereocenters in a single operation, demonstrating high diastereoselectivity.

Conclusions:

• The presented synthetic strategy offers a significant advancement in the preparation of complex antibiotic fragments.
• This scalable route facilitates the potential large-scale production of iboxamycin, cresomycin, and BT-33 analogs.