title: Catalytic asymmetric formal synthesis of beraprost.
abstract: The first catalytic asymmetric synthesis of the key intermediate for beraprost has been achieved through an enantioselective intramolecular oxa-Michael reaction of an α,β-unsaturated amide mediated by a newly developed benzothiadiazine catalyst. The Weinreb amide moiety and bromo substituent of the Michael adduct were utilized for the C-C bond formations to construct the scaffold. All four contiguous stereocenters of the tricyclic core were controlled via Rh-catalyzed stereoselective C-H insertion and the subsequent reduction from the convex face.
authors.affiliation: Graduate School of Pharmaceutical Sciences, Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8501, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Kobayashi
authors.affiliation: Graduate School of Pharmaceutical Sciences, Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8501, Japan.
authors.forename: Ryuta
authors.initials: R
authors.lastname: Kuramoto
authors.affiliation: Graduate School of Pharmaceutical Sciences, Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8501, Japan.
authors.forename: Yoshiji
authors.initials: Y
authors.lastname: Takemoto
keywords: bifunctional catalysis; hydrogen bonding; organocatalyst; oxa-Michael; prostacyclin