Synthesis of Nonracemic 1,4-Benzoxazines via Ring Opening/Cyclization of Activated Aziridines with 2-Halophenols: Formal Synthesis of Levofloxacin
Abhijit Mal, Imtiyaz Ahmad Wani, Gaurav Goswami and Manas K. Ghorai*
*Department of Chemistry, Indian Institute of Technology, Kanpur 208016, India, Email: mkghoraiiitk.ac.in
A. Mal, I. A. Wani, G. Goswami, M. K. Ghorai, J. Org. Chem., 2018, 83, 7907-7918.
DOI: 10.1021/acs.joc.8b00788 (free Supporting Information)
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An efficient synthesis of 3,4-dihydro-1,4-benzoxazine derivatives in excellent enantio- and diastereospecificity (ee > 99%, de > 99%) proceeds via Lewis acid-catalyzed SN2-type ring opening of activated aziridines with 2-halophenols followed by Cu(I)-catalyzed intramolecular C-N cyclization in a stepwise fashion.
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