Metal-Free, One-Pot Cascade Annulation of 2-Pyrones in Water for the Synthesis of Peptidomimetics
作者:Wannaporn Disadee、Anek Lekky、Somsak Ruchirawat
DOI:10.1021/acs.joc.9b01856
日期:2020.2.21
formation, decarboxylation or esterification, isomerization, and lactamization, to furnish bicyclic 2-pyridones in up to 98% yield with retention of the chirality at the α-carbon of the amino acid portion of the molecule. Exploration of the substrate scope revealed some selectivity between the decarboxylation and esterification pathways under thermal acidic conditions, while performing the reaction in boiling
seen as precursors of various heterocyclic rings. Although γ-amino-ynones have been used to prepare exocyclic vinylogous amides in the presence of Bronsted acids, we describe here the use of zinc chloride as a weak Lewis acid for their conversion into acetylenic cyclic imines. This reaction, which was attempted for a diverse range of γ-amino-ynones, proved to be robust and efficient in most cases and