An efficient total synthesis of (-)-epothilone B.

Area of Science:

• Organic Chemistry
• Synthetic Chemistry
• Medicinal Chemistry

Background:

• Epothilones are a class of potent anti-cancer agents.
• Developing efficient synthetic routes for epothilones is crucial for their therapeutic application.
• Previous syntheses have faced challenges in scalability and efficiency.

Purpose of the Study:

• To develop an efficient and scalable total synthesis of (-)-epothilone B.
• To establish a new synthetic strategy for accessing complex polyketide natural products.
• To provide a foundation for the industrial production of epothilone B and ixabepilone.

Main Methods:

• A convergent synthesis strategy was employed.
• A key step involved a bissiloxane-tethered ring-closing metathesis reaction.
• The synthesis was optimized for efficiency and step economy.

Main Results:

• (-)-Epothilone B was synthesized in approximately 8% overall yield.
• The synthesis was completed in 11 steps from advanced intermediate 9 (or 10 steps from 7/8).
• The novel ring-closing metathesis effectively formed the required trisubstituted (Z) double bond.

Conclusions:

• The developed synthetic route is efficient and offers a new basis for industrial process development.
• This synthesis provides a viable pathway for the large-scale production of epothilone B and ixabepilone.
• The employed methodology can be applied to the synthesis of other complex natural products.