Free radical 5-exo-dig cyclization as the key step in the synthesis of bis-butyrolactone natural products: experimental and theoretical studies

Sharma, Gangavaram V. M.; Harinada Chary, Devoju; Chandramouli, Nagula; Achrainer, Florian; Patrudu, Sateesh und Zipse, Hendrik (2011): Free radical 5-exo-dig cyclization as the key step in the synthesis of bis-butyrolactone natural products: experimental and theoretical studies. In: Organic & Biomolecular Chemistry, Bd. 9, Nr. 11: S. 4079-4084

Abstract

Radical cyclization reactions were performed by 5-exo-dig mode to yield cis-fused bicyclic systems, leading to the synthesis of bis-butyrolactone class of natural products. The study was aimed at understanding the impact of alkyl side chains of furanoside ring systems in L-ara configuration on the radical cyclization. It was amply demonstrated by experimental studies that the increase in the length of the alkyl side chain has an effect on the cyclization: while efficient cyclization reactions could be realized with methyl and ethyl side chains, the yields were significantly reduced in the case of n-pentyl side chain. Theoretical studies using DFT and (RO)MP2 methods were carried out to analyze the influence of the substitution pattern on the cyclization barriers.

• Dokumententyp: Zeitschriftenartikel
• Fakultät: Chemie und Pharmazie
• Themengebiete: 500 Naturwissenschaften und Mathematik > 540 Chemie
• Allianz-/Nationallizenz: Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
• Sprache: Englisch