Enantioselective Cyclopropanation with α-Alkyl-α-diazoesters Catalyzed by Chiral Oxazaborolidinium Ion: Total Synthesis of (+)-Hamavellone B

Autor: Jae Yeon Kim, Do Hyun Ryu, Su Yong Shim, Geum-Sook Hwang, Miso Nam
Rok vydání: 2016
Předmět:
Zdroj: Organic letters. 18(2)
ISSN: 1523-7052
Popis: Chiral oxazaborolidinium ion-catalyzed asymmetric cyclopropanation of α- or α,β-substituted acroleins with α-alkyl-α-diazoesters has been developed. With this methodology, chiral functionalized cyclopropanes containing a quaternary stereogenic center were obtained with high to excellent enantioselectivities (up to >99% ee). The synthetic utility of optically enriched functionalized cyclopropane was demonstrated in the first total synthesis of (+)-hamavellone B, which establishes the absolute configuration of natural (+)-hamavellone B.
Databáze: OpenAIRE