Asymmetric Synthesis of a 5,7-Fused Ring System Enabled by an Intramolecular Buchner Reaction with Chiral Rhodium Catalyst
Hoshi, T.; Ota, E.; Inokuma, Y.; Yamaguchi, J.
Org. Lett.. 2019, ASAP.
DOI: 10.1021/acs.orglett.9b04048
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.
