Exploiting orthogonally reactive functionality: synthesis and stereochemical assignment of (-)-ushikulide A

Area of Science:

• Organic Chemistry
• Natural Product Synthesis
• Spectroscopic Methods

Background:

• Modern spectroscopic methods are advanced, yet organic synthesis remains crucial for complex natural product structure elucidation.
• Organic synthesis offers a logical approach to determine structures, even without initial assignments, by combining logic and spectroscopic data.
• Ushikulide A, a newly isolated natural product from the oligomycin-rutamycin family, was previously stereochemically undefined.

Purpose of the Study:

• To report the execution of an organic synthesis strategy for the structural elucidation of ushikulide A.
• To achieve efficient synthesis and stereochemical assignment of ushikulide A.
• To demonstrate the utility of combining logic and spectroscopic comparison in natural product synthesis.

Main Methods:

• Utilized organic synthesis as a pivotal tool for structure elucidation.
• Employed chemoselective manipulation of orthogonally reactive functional groups, including alkenes and alkynes.
• Used alkenes and alkynes as surrogates for carbonyl and hydroxyl functionalities to enhance synthetic efficiency.

Main Results:

• Successfully executed a strategy for the synthesis and stereochemical assignment of ushikulide A.
• Minimized the number of synthetic steps and protecting groups required.
• Demonstrated the effectiveness of using alkenes and alkynes as functional group surrogates.

Conclusions:

• The reported strategy efficiently led to the synthesis and stereochemical assignment of ushikulide A.
• Chemoselective manipulation of functional groups proved advantageous in streamlining the synthetic route.
• Organic synthesis remains indispensable for defining the structures of complex natural products.