Diastereoselective Ring Expansion of Cyclic Ketones Enabled by HAT-Initiated Radical Cascade

Org Lett. 2023 Nov 10;25(44):8022-8026. doi: 10.1021/acs.orglett.3c03236. Epub 2023 Oct 27.

Abstract

Herein we disclose an iron-catalyzed method for stereoselective synthesis of multisubstituted cyclic ketones containing a synthetically challenging quaternary carbon from readily accessible β-vinyl keto esters in good yields. This cascade reaction is initiated by a hydrogen atom transfer (HAT) process, after which a Dowd-Beckwith-type ring-expansion reaction occurs. This strategic transformation offers access to synthetically valuable cyclic ketones bearing two contiguous stereocenters, including quaternary stereocenters, which hold paramount significance within the realm of synthetic chemistry.