Bioinspired Total Synthesis of (−)‐Vescalin: A Nonahydroxytriphenoylated C‐Glucosidic Ellagitannin. Issue 44 (27th September 2017)

• Record Type: Journal Article
• Authors: Richieu, Antoine; Peixoto, Philippe A.; Pouységu, Laurent; Deffieux, Denis; Quideau, Stéphane
• Is Part Of: Angewandte Chemie international edition. Volume 56:Issue 44(2017)
• Page Start: 13833
• Page End: 13837
• Publication Date: 2017-09-27
• Subjects: copper -- natural products -- oxidative coupling -- polyphenols -- total synthesis; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201707613
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: The first total synthesis of the 2, 3, 5‐ O ‐( S, R )‐nonahydroxytriphenoylated (NHTP) C ‐glucosidic ellagitannin (−)‐vescalin was accomplished through a series of transformations mimicking the sequence of events leading to its biogenesis. The key steps of this synthesis encompass a Wittig‐mediated ring opening of a glucopyranosic hemiacetal, a C‐glucosidation event through a phenolic aldol‐type reaction, and a Wynberg–Feringa–Yamada‐type oxidative phenolic coupling, which forged the NHTP unit of (−)‐vescalin. Abstract : Catch a tan(nin) : The total synthesis of a first member of the nonahydroxytriphenoylated (NHTP) C ‐glucosidic ellagitannins, (−)‐vescalin, is described. The route is closely tailored to the commonly proposed sequence of events leading to its biogenesis. Its characteristic 2, 3, 5‐( S, R )‐NHTP unit was elaborated by a copper(II)‐mediated Wynberg–Feringa–Yamada‐type phenolic coupling using the achiral bicyclic diamine N, N ′‐dimethylbispidine.