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Updated: May 15, 2026
![Solid-phase Synthesis of [4.4] Spirocyclic Oximes](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F58508.jpg&w=3840&q=50)
Solid-phase Synthesis of [4.4] Spirocyclic Oximes
Published on: February 6, 2019
Total Synthesis of Allocyclinone A via Late-Stage Halogen Swapping
Tsung-Han Chao1, Elizabeth B Barrois2, Chad W Johnston2
1Department of Chemistry, Rice University, BioScience Research Collaborative, Houston, USA.
Abstract:
Allocyclinones A-D are small congeners of angucyclinones with several unusual structural features and potent antibiotic activity against various Gram-positive pathogens. Allocyclinone A, the most active congener, contains an intriguing aromatic trichloromethyl substituent that has never been observed in other natural products before. In this study, we report a modular total synthesis of allocyclinones A and B featuring the convergent assembly of three key building blocks through Hauser annulation and cross-couplings. The synthesis of allocyclinone A was made possible by the application of a late-stage trifluoromethyl-to-trichloromethyl swap, providing a potentially generalizable strategy for aromatic trichloromethyl installation in complex settings. The antibiotic activity of the scaffold was also verified, and attempts to elucidate its mode of action were performed.
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