Synthesis of α,β-Unsaturated α'-Haloketones through the Chemoselective Addition of Halomethyllithiums to Weinreb Amides
Vittorio Pace*, Laura Castoldi and Wolfgang Holzer
*Department of Drug and Natural Product Synthesis, University of Vienna, Althanstrasse 14, Vienna, A-1090, Austria, Email: vittorio.paceunivie.ac.at
V. Pace, L. Castoldi, W. Holzer, J. Org. Chem., 2013, 78, 7764-7770.
DOI: 10.1021/jo401236t (free Supporting Information)
A chemoselective addition of halomethyllithium carbenoids to Weinreb amides at -78°C enables a straightforward synthesis of variously functionalized α,β-unsaturated α'-haloketones. The exceptional stability of the intermediate furnished by the N-methoxy group does not allow a 2nd addition of LiCH2X and thus prevents from formation of carbinols.
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