The synthesis of new chiral highly functionalized zwitterionic bicyclic lactams starting from acyclic β-enaminoesters derived from ()-(-)-2-phenylglycinol is described. The key step involved an intramolecular non-classical Corey-Chaykovsky ring-closing reaction of the corresponding sulfonium salts derived from β-enaminoesters. This methodology permits the generation of two or three new stereogenic centers with high diastereoselectivity. The utility of these intermediates was demonstrated by the stereocontrolled total synthesis of -4-hydroxy-2-methyl piperidine and its corresponding pipecolic acid derivative.
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| http://dx.doi.org/10.1039/d1ra09298g | DOI Listing |
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