Spin Trapping of ¹³C‐Labeled <i>p</i>‐Benzynes Generated by Masamune–Bergman Cyclization of Bicyclic Nine‐Membered Enediynes

Abstract

A new spin on things? Spin trapping of 13C-labeled bicyclic mimics of natural nine-membered enediynes provided persuasive evidence for the spontaneous thermal generation of biradicals 1 and the differential reactivity of the resulting C3 and C6 radical centers (see scheme; ST spin trap; TBS tert-butyldimethylsilyl).