A one-pot grain-scale synthetic route for the preparation of gamma-hydroxybutenolides via catalyst-free annulation of alpha-amino acids with alpha-keto acids in water is reported. The method shows many advantages such as readily available starting materials, mild reaction conditions, operational simplicity, acceptable yields, and requiring no extra catalysts or additions. Furthermore, the method is innocuous to the environment, also is valuable to industry. (C) 2017 Elsevier Ltd. All rights reserved.
Stereodivergent Synthesis of Enantioenriched 2-Pyrrolidones via Diastereoselective Hydrogenation of α,β-Unsaturated γ-Lactams
作者:Siyuan Guo、Baode Ma、Gen-Qiang Chen、Xumu Zhang
DOI:10.1021/acs.orglett.3c00532
日期:——
Synthesis of optically enriched racetam analogues was achieved via highly remote diastereocontrolled and enantiocontrolled Pd/C-catalyzed hydrogenation of α,β-unsaturated γ-lactams. Various mono- and disubstituted 2-pyrrolidones were obtained in excellent yields and stereoselectivities, and a concise and large-scale synthesis of brivaracetam was developed from inexpensive l-2-aminobutyric acid. Surprisingly