Total synthesis of nafuredin B

Area of Science:

• Organic Chemistry
• Natural Product Synthesis
• Marine Biology

Background:

• Marine secondary metabolites are a rich source of novel chemical structures with potential biological activities.
• Nafuredin B is a marine natural product whose total synthesis has not been previously reported.
• Establishing efficient synthetic routes to complex natural products is crucial for further biological investigation and analog development.

Purpose of the Study:

• To achieve the first total synthesis of nafuredin B.
• To confirm the proposed structure of nafuredin B through synthesis.
• To develop a convergent synthetic strategy applicable to related marine natural products.

Main Methods:

• Convergent synthesis strategy.
• Sharpless asymmetric epoxidation and epoxide opening for stereocenter installation.
• Iterative olefination reactions (Julia-Kocienski, Wittig, HWE) for alkene formation.
• Ring-closing metathesis for δ-lactone ring construction.

Main Results:

• Successful total synthesis of nafuredin B.
• Installation of the tetrasubstituted hydroxy center via stereoselective epoxidation and opening.
• Construction of multiple olefin bonds using iterative olefination techniques.
• Formation of the unsaturated δ-lactone core through ring-closing metathesis.
• Unambiguous structural confirmation of nafuredin B.

Conclusions:

• The first total synthesis of nafuredin B was accomplished.
• The synthetic route provides definitive structural proof for the isolated marine natural product.
• The developed convergent strategy highlights the utility of key reactions in complex molecule synthesis.