Direct observation of ESR spectra of bicyclic nine-membered enediynes at ambient temperature

作者：Hirama Masahiro^*; Akiyama Kimio; Das Parthasarathi; Mita Takashi; Lear Martin J; Iida Kyo ichiro; Sato Itaru; Yoshimura Furnihiko; Usuki Toyonobu; Tero Kubota Shozo

来源：Heterocycles, 2006, 69(1): 83-+.

DOI：10.3987/com-06-s(o)22

• enediyne
• p-benzyne
• radical
• Masamune-Bergman reaction
• ESR spectra

The ESR spectra for synthetic bicyclo[7.3.0]epoxydodecadienediynes in solution at room temperature are steady. These spectra originate from the Masamune-Bergman cyclization of bicyclo[7.3.0]epoxydodecadienediynes to p-benzyne biradicals and the equilibrium between the two forms. Comparison of the ESR spectra of the unlabeled and C-13-labeled nine-membered enediynes indicated that the spectra are not directly due to the p-benzyne biradicals but rather to more stable secondary radical intermediates.

• 出版日期2006-12-1