EPC-synthesis and fungistatic activity of a gloeosporone analog with an ω-hydroxybutyl instead of the pentyl side chain on the macrocyclic ring
✍ Scribed by Seebach, Dieter ;Adam, Geo ;von dem Bussche-Hünnefeld, Christoph ;Gisi, Ulrich ;Binder, Heinz
- Publisher
- John Wiley and Sons
- Year
- 1990
- Tongue
- English
- Weight
- 677 KB
- Volume
- 1990
- Category
- Article
- ISSN
- 0947-3440
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✦ Synopsis
Abstract
(+)‐5′‐Oxa‐gloeosporone (2), an analog of the natural germination self‐inhibitor (−)‐gloeosporone (1), is synthesized, largely following our previously published route to the parent compound. Thus, the hydroxybutyl side chain of 2 was introduced by hydroboration of a butenyl group (→ 14) which had been carried along throughout the synthesis up to the stage of the 14‐membered yne‐lactone 13. Silyl protection (→ 15), oxidation of the acetylene to a 1,2‐diketone moiety (→ 16), and deprotection with spontaneous intramolecular hemiacetal formation completed the synthesis of (+)‐2. The (+)‐oxa‐gloeosporone 2 exhibits an in vitro and in vivo antifungal activity spectrum with 14 microorganisms very similar to both the natural (1) and the unnatural enantiomer (ent‐1) of gloeosporone, indicating that neither the sense of chirality nor the side‐chain structure is important for the mode of action.