Synlett 2019; 30(12): 1447-1451
DOI: 10.1055/s-0037-1611552
letter
© Georg Thieme Verlag Stuttgart · New York

Diastereoselective Synthesis of γ-Lactams and δ-Lactams via a Conjugate Addition-Initiated Tandem Reaction

Miaomiao Gan
,
Lan Jiang
,
Zhengning Li*
College of Environmental and Chemical Engineering, Dalian University, Dalian 116622, P. R. of China   Email: znli@dl.cn
› Author Affiliations
Further Information

Publication History

Received: 20 April 2019

Accepted after revision: 29 April 2019

Publication Date:
20 May 2019 (eFirst)

Abstract

β-Alkoxycarbonyl-γ-lactams and γ-alkoxycarbonyl-δ-lactams were synthesized via a conjugate alkylation/Mannich reaction/lactamization tandem reaction of unsaturated dicarboxylates with diethyl zinc and aldimines. The high yield, the ready availability of the reagents, and especially the high diastereoselectivity are promising characteristics of the approach that allows access to functionalized lactams.

Supporting Information

 
  • References and Notes

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    • This does not conclusively rule out other mechanisms; for example, a radical-polar mechanism, as one referee suggested, might be triggered by radical initiator introduced adventitiously, see:
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  • 19 CCDC 1896065 and 1896064 contain the supplementary crystallographic data for this paper (major isomers of 5a and 5h, respectively). The data can be obtained free of charge from The Cambridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/getstructures.