Asymmetric Synthesis of a 5,7-Fused Ring System Enabled by an Intramolecular Buchner Reaction with Chiral Rhodium Catalyst

Takayuki Hoshi; Eisuke Ota; Yasuhide Inokuma; Junichiro Yamaguchi

doi:10.1021/acs.orglett.9b04048

Asymmetric Synthesis of a 5,7-Fused Ring System Enabled by an Intramolecular Buchner Reaction with Chiral Rhodium Catalyst

Org Lett. 2019 Dec 20;21(24):10081-10084. doi: 10.1021/acs.orglett.9b04048. Epub 2019 Dec 6.

Authors

Takayuki Hoshi¹, Eisuke Ota¹, Yasuhide Inokuma², Junichiro Yamaguchi¹

Affiliations

¹ Department of Applied Chemistry , Waseda University , 3-4-1 Ohkubo , Shinjuku , Tokyo 169-8555 , Japan.
² Division of Applied Chemistry, Faculty of Engineering , Hokkaido University , Kita 13 Nishi 8 Kita-ku , Sapporo , Hokkaido 060-8628 , Japan.

PMID: 31808701
DOI: 10.1021/acs.orglett.9b04048

Abstract

A Rh-catalyzed asymmetric intramolecular Buchner ring expansion of α-alkyl-α-diazoesters has been developed. The present protocol generates a 5,7-fused ring system in an enantioselective manner while minimizing β-hydrogen migration, which has been a competing reaction when using α-alkyl-α-diazoesters. The ester functionality at the bridgehead position would be a useful synthetic handle for further derivatization to complex molecules including natural products.