Contrasting C- and O-Atom Reactivities of Neutral Ketone and Enolate Forms of 3-Sulfonyloxyimino-2-methyl-1-phenyl-1-butanones
Yingtang Ning, Yuko Otani and Tomohiko Ohwada*
*Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku Tokyo 113-0033, Japan, Email: ohwadamol.f.u-tokyo.ac.jp
Y. Ning, Y. Otani, T. Ohwada, J. Org. Chem., 2018, 83, 203-219.
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The ketone, enol, and enolate forms of 3-sulfonyloxyimino-2-methyl-1-phenyl-1-butanones can afford different intramolecular cyclization products, depending on the conditions. Reactions under basic conditions afford 2H-azirines via a neutral enol (DABCO) or isoxazoles and oxazoles via an anionic enolate (t-BuOK), while acidic conditions afford oxazoles (AcOH) and isoxales (TFA) via neutral ketones.
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