Multiply unsaturated and [omega]‐brominated [beta]‐ketothioesters for synthesizing [beta]‐ketolactams and the scaffolds of fully enolized N‐hydroxy‐3‐(polyenoyl)pyridine‐2,4‐dione natural products

Abstract: Fully enolized N-hydroxypyridine-2,4-diones with a 3-enoyl or 3-dienoyl or 3-trienoyl substituent (collectively named “3-polyenoyl substituent“ hereafter) define the core of a number of δ-lactam natural products. We developed a strategy for establishing such motifs in a convergent and stereoselective manner. The polyenoyl moiety of our target molecules stemmed from simply, two-fold or three-fold unsaturated and almost completely enolized ω-bromo-β-ketothioesters, two of which were obtained for the first time. The N-bound hydroxy group of our target structures originated from an O-(2,4,6-trimethoxybenzyl)-protected β-(hydroxylamino)propionic ester, first obtained in this study, too. The mentioned building blocks were combined intermolecularly by a thioester hydroxylaminolysis and thereafter intramolecularly by a Williams-type Dieckmann cyclization. The resulting N-(2,4,6-trimethoxybenzyloxy)dihydropyridine-2,4-diones were oxidized with CBrCl3 and DBU. The N-(2,4,6-trimethoxybenzyloxy)pyridine-2,4-diones gained thereby were debenzylated – jointly with their (4-methoxybenzyl) aryl ether moiety – with F3CCO2H. This liberated the target structures

Show object

• Location: Deutsche Nationalbibliothek Frankfurt am Main
• Extent: Online-Ressource
• Language: Englisch
• Notes: European journal of organic chemistry. - 27, 4 (2024) , e202301001, ISSN: 1099-0690

Contributors, Places and Time

• Event: Veröffentlichung
• (where): Freiburg
• (who): Universität
• (when): 2024
• Creator: Kopp, Julia ; Brückner, Reinhard

Further information

• DOI: 10.1002/ejoc.202301001
• URN: urn:nbn:de:bsz:25-freidok-2428333
• Rights: Open Access; Der Zugriff auf das Objekt ist unbeschränkt möglich.