Stereoselective Synthesis of the I–L Fragment of the Pacific Ciguatoxins
The I–L ring system found in all the Pacific ciguatoxins has been prepared from a tricyclic precursor in a highly stereoselective manner. Subtle differences in the reactivity of the enones present in the seven- and eight-membered rings of the tricyclic ether starting material have been exploited to...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2020-11-01
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| Series: | Toxins |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2072-6651/12/12/740 |
| Summary: | The I–L ring system found in all the Pacific ciguatoxins has been prepared from a tricyclic precursor in a highly stereoselective manner. Subtle differences in the reactivity of the enones present in the seven- and eight-membered rings of the tricyclic ether starting material have been exploited to allow selective protection of the enone in the eight-membered ring. Subsequent distereoselective allylation of the seven-membered ring has been accomplished by a palladium-mediated Tsuji-Trost reaction. The K-ring methyl and hydroxyl groups have been installed in a highly stereoselective manner by sequential conjugate reduction and enolate oxidation reactions. Ring L has been constructed by a use of a novel relay ring-closing metathesis reaction to complete the tetracyclic framework, which possesses the functionality necessary for elaboration of rings I and L and the introduction of ring M. |
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| ISSN: | 2072-6651 |