Diastereoselective synthesis of new zwitterionic bicyclic lactams, scaffolds for construction of 2-substituted-4-hydroxy piperidine and its pipecolic acid derivatives?

RSC Advances Pub Date: 2022-02-02 DOI: 10.1039/D1RA09298G

Abstract

The synthesis of new chiral highly functionalized zwitterionic bicyclic lactams starting from acyclic β-enaminoesters derived from (R)-(?)-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 cis-4-hydroxy-2-methyl piperidine and its corresponding pipecolic acid derivative.

Graphical abstract: Diastereoselective synthesis of new zwitterionic bicyclic lactams, scaffolds for construction of 2-substituted-4-hydroxy piperidine and its pipecolic acid derivatives
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