Approaches to phomactin A: unexpected late-stage observations

作者：Burnell Erica S; Irshad Abdur Rehman; Raftery James; Thomas Eric J^*

来源：Tetrahedron Letters, 2015, 56(23): 3255-3258.

DOI：10.1016/j.tetlet.2015.01.082

• Natural products
• Diastereoselectivity
• Epoxide cleavage
• TPAP oxidation
• Macrocyclisation

A dihydroxyepoxide analogous to that proposed as a late intermediate in the biosynthesis of phomactin A was prepared by reduction of the corresponding ketoaldehyde. The structure of the dihydroxyepoxide, specifically its configuration at C14, was confirmed by the X-ray crystal structure of its diacetate. The stereoselectivity of reduction of the ketoaldehyde would appear to be influenced by the presence of a remote phenylsulphonyl moiety at C10. Of interest in the context of the biosynthesis of phomactin A was the observation that this dihydroxyepoxide did not rearrange into the isomeric hydroxytetrahydropyran despite having the configuration at C14 required for this rearrangement.

• 出版日期2015-6-3