TY  - JOUR
A1  - Krüger, Tobias
A1  - Kelling, Alexandra
A1  - Schilde, Uwe
A1  - Linker, Torsten
T1  - Simple Synthesis of gamma-Spirolactams by Birch Reduction of Benzoic Acids
JF  - European journal of organic chemistry
N2  - A convenient synthesis of gamma-spirolactams in only two steps was developed. Birch reduction of benzoic acids and immediate alkylation with chloroacetonitrile afforded cyclohexadienes in high yields. The products could be isolated by crystallization on a large scale in analytically pure form. Subsequent hydrogenation with platinum(IV) oxide as the catalyst reduced the nitrile functionality and the double bonds in the same step with excellent stereoselectivity. The relative configurations were determined unequivocally by X-ray analyses. Direct cyclization of the intermediary formed amino acids afforded the desired gamma-spirolactams in excellent overall yields. The procedure is characterized by few steps, cheap reagents, and can be performed on a large scale, interesting for industrial processes.
KW  - Diastereoselectivity
KW  - Hydrogenation
KW  - Lactams
KW  - Reduction
KW  - Synthetic methods
Y1  - 2016
U6  - https://doi.org/10.1002/ejoc.201601650
SN  - 1434-193X
SN  - 1099-0690
IS  - 6
SP  - 1074
EP  - 1077
PB  - Wiley-VCH
CY  - Weinheim
ER  -