A Bioinspired Approach toward the Complex Cyclotaxane Taxpropellane

Area of Science:

• Natural Product Chemistry
• Organic Synthesis
• Medicinal Chemistry

Background:

• Taxopropellanes are structurally complex taxanes with unique fused ring systems.
• Their intricate scaffolds present significant synthetic challenges.
• Understanding taxopropellane biosynthesis offers insights into taxane diversity.

Purpose of the Study:

• To develop an efficient bioinspired semisynthesis of a C1,C7-oxygenated taxopropellane analogue.
• To explore the construction of the complex taxopropellane core.
• To investigate the cytotoxic potential of synthetic taxopropellane analogues.

Main Methods:

• Semisynthesis from 10-deacetylbaccatin III in 15 steps.
• Utilized a bioinspired singlet oxygen ene reaction.
• Employed a [2+2] cycloaddition/hemiketalization cascade reaction.

Main Results:

• Successfully synthesized a C1,C7-oxygenated taxopropellane analogue (18).
• Efficiently assembled the hexacyclic taxopropellane core in a single cascade step.
• Identified synthetic analogues (41, 42) with potent cytotoxicity against cancer cell lines.

Conclusions:

• The developed method provides efficient access to complex taxopropellane structures.
• This work deepens the understanding of biosynthetic relationships within the taxane family.
• Synthetic taxopropellane analogues show promise as anticancer agents.