Concise total synthesis of (+)-aspergillide B.

Area of Science:

• Organic Chemistry
• Synthetic Chemistry
• Natural Product Synthesis

Background:

• Aspergillide B is a complex natural product with a challenging molecular structure.
• Previous structural assignments for aspergillide B required confirmation through synthesis.
• Efficient synthetic routes are crucial for accessing and studying complex natural products.

Purpose of the Study:

• To achieve an efficient total synthesis of (+)-aspergillide B.
• To confirm the revised structure of aspergillide B.
• To develop and showcase novel synthetic methodologies for complex molecule construction.

Main Methods:

• Utilized C-glycosylation for the construction of the 2,6-trans-substituted pyran core.
• Developed a highly effective four-step sequence for key intermediate 13 production without purification.
• Employed an E-selective Julia-Kocienski olefination on a complex substrate.

Main Results:

• Successfully completed the total synthesis of (+)-aspergillide B.
• The synthetic route efficiently produced a key intermediate in four steps.
• The synthesis validated the revised structure of aspergillide B.

Conclusions:

• The developed synthetic strategy is efficient and effective for producing (+)-aspergillide B.
• The synthesis provides definitive confirmation of the revised aspergillide B structure.
• The employed C-glycosylation and Julia-Kocienski olefination reactions are valuable tools in complex molecule synthesis.