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Synthesis of γ‐Spirolactams by Birch Reduction of Arenes
Author(s) -
Krüger Tobias,
Linker Torsten
Publication year - 2021
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.202100056
Subject(s) - chemistry , benzoic acid , stereocenter , birch reduction , diastereomer , catalysis , organic chemistry , combinatorial chemistry , enantioselective synthesis
A convenient method for the synthesis of γ‐spirolactams in only three steps is described. Birch reduction of inexpensive and commercially available aromatic carboxylic acids in the presence of chloroacetonitrile affords nitriles in moderate to good yields. Suitable precursors are methyl‐substituted benzoic acids, naphthoic, and anthroic acid. Subsequent catalytic hydrogenation proceeds smoothly with PtO 2 or Raney Ni as catalysts and lactams are isolated in excellent yields and stereoselectivities. Thus, up to 3 new stereogenic centers can be constructed as sole diastereomers from achiral benzoic acids. Furthermore, it is possible to control the degree of saturation at different pressures, affording products with 0, 1, or 2 double bonds. Overall, more than 15 new γ‐spirolactams have been synthesized in analytically pure form.