Asymmetric Total Synthesis of Leptosphin C

Area of Science:

• Organic Chemistry
• Synthetic Chemistry
• Natural Product Synthesis

Background:

• Leptosphine C is a complex natural product with potential biological significance.
• Efficient synthetic routes are crucial for accessing and studying such molecules.

Purpose of the Study:

• To develop a concise and enantioselective total synthesis of leptosphine C.
• To showcase the utility of novel synthetic methodologies.

Main Methods:

• Enantioselective Hajos-Parrish-Eder-Sauer-Wiechert (HPESW) reaction for AB ring construction.
• Pauson-Khand (PK) reaction for CD ring system formation, including a quaternary carbon.

Main Results:

• Successful construction of the AB ring system with high diastereoselectivity (dr = 19:1) and enantioselectivity (90% ee).
• Efficient establishment of the CD ring system featuring a quaternary carbon at C14.
• Overall concise and enantioselective total synthesis of leptosphine C (1) achieved with 76% yield.

Conclusions:

• The developed synthetic strategy provides an efficient route to leptosphine C.
• The study highlights the power of combining HPESW and PK reactions in complex molecule synthesis.