Total Synthesis of (+)-Haperforin G

Area of Science:

• Organic Chemistry
• Synthetic Chemistry
• Medicinal Chemistry

Background:

• (+)-Haperforin G is a complex natural product with potential biological activities.
• Efficient and scalable synthetic routes are crucial for further biological evaluation and analog development.
• Existing synthetic methods may lack efficiency or stereoselectivity.

Purpose of the Study:

• To develop a concise and efficient total synthesis of (+)-haperforin G.
• To establish novel synthetic methodologies applicable to complex molecule synthesis.
• To enable the preparation of structurally diverse analogs for structure-activity relationship studies.

Main Methods:

• Cobalt-catalyzed intramolecular Pauson-Khand reaction for stereoselective cyclopentanone construction.
• Light-initiated photocatalysis for asymmetric cross-coupling of unstabilized C(sp³)-radicals with enones.
• Multi-step synthesis from commercially available starting materials.

Main Results:

• A 20-step synthesis of (+)-haperforin G was successfully achieved.
• The synthesis features the stereoselective formation of a quaternary stereogenic center.
• The developed photocatalytic method allows for convergent and asymmetric radical cross-coupling.
• The methodology provides access to structurally diverse analogs of haperforin G.

Conclusions:

• The developed synthetic strategy is efficient and versatile.
• The new chemical transformations are valuable tools for complex natural product synthesis.
• This work facilitates further exploration of haperforin G analogs and their biological properties.