Biomimetic Total Syntheses of (−)‐Leucoridines A and C through the Dimerization of (−)‐Dihydrovalparicine. Issue 43 (28th August 2015)

• Record Type: Journal Article
• Authors: Kokkonda, Praveen; Brown, Keaon R.; Seguin, Trevor J.; Wheeler, Steven E.; Vaddypally, Shivaiah; Zdilla, Michael J.; Andrade, Rodrigo B.
• Is Part Of: Angewandte Chemie international edition. Volume 54:Issue 43(2015)
• Page Start: 12632
• Page End: 12635
• Publication Date: 2015-08-28
• Subjects: biomimetic synthesis -- indole alkaloids -- natural products -- reaction mechanisms -- total synthesis; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201505198
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: Concise biomimetic syntheses of the Strychnos‐Strychnos‐type bis‐indole alkaloids (−)‐leucoridine A (1 ) and C (2 ) were accomplished through the biomimetic dimerization of (−)‐dihydrovalparicine (3 ). En route to3, the known alkaloids (+)‐geissoschizoline (8 ) and (−)‐dehydrogeissoschizoline (10 ) were also prepared. DFT calculations were employed to elucidate the mechanism, which favors a stepwise aza‐Michael/spirocyclization sequence over the alternate hetero‐Diels–Alder cycloaddition reaction. Abstract : Concise biomimetic syntheses of the Strychnos‐Strychnos ‐type bis‐indole alkaloids (−)‐leucoridine A and C were accomplished through the biomimetic dimerization of (−)‐dihydrovalparicine. DFT calculations were used to elucidate the mechanism, which favors a stepwise aza‐Michael/spirocyclization sequence over the alternate hetero‐Diels–Alder cycloaddition reaction.