Total Synthesis and Structure Assignment of Saptomycin H
Jun Shimura1, Yoshio Ando1, Ken Ohmori1
1Department of Chemistry, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro-ku, Tokyo 152-8551, Japan.
Organic Letters
|February 11, 2022
Summary
The first total synthesis of saptomycin H was achieved, determining the absolute stereochemistry of its oxiranyl side chain as 14R,16S. Key steps included assembling anthrone, sugar, and side chain units, and forming the pyranone A-ring.
Area of Science:
- Organic Chemistry
- Synthetic Chemistry
- Natural Product Synthesis
Background:
- Saptomycin H is a complex natural product with potential biological significance.
- The absolute stereochemistry of its oxiranyl side chain was previously undetermined.
- Total synthesis provides a route to confirm structure and enable further studies.
Purpose of the Study:
- To achieve the first total synthesis of saptomycin H.
- To determine the absolute stereochemistry of the oxiranyl side chain.
- To establish a synthetic route for potential analog development.
Main Methods:
- Concise three-unit assembly strategy (anthrone, sugar, side chain).
- AZADOL-mediated 6-endo-selective pyranone (A-ring) formation.
- Stereoselective synthesis and characterization.
Main Results:
- Successful total synthesis of saptomycin H (2).
- Determination of the oxiranyl side chain absolute stereochemistry as 14R,16S.
- Efficient construction of the A-ring via a novel cyclization.
Conclusions:
- The first total synthesis of saptomycin H is reported.
- The absolute stereochemistry of the oxiranyl side chain is confirmed as 14R,16S.
- The developed synthetic strategy is efficient and highlights key bond formations.
