Premium
2,6‐Piperidinediones, II. Absolute Configuration of the Enantiomers of 3,3‐Disubstituted 2,6‐Piperidinediones
Author(s) -
Knabe Joachim,
Reischig Dirk
Publication year - 1984
Publication title -
archiv der pharmazie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.468
H-Index - 61
eISSN - 1521-4184
pISSN - 0365-6233
DOI - 10.1002/ardp.19843170511
Subject(s) - absolute configuration , chemistry , enantiomer , glutethimide , stereochemistry , walden inversion , spectral line , physics , psychology , psychiatry , astronomy
Determination of the absolute configuration of the 2,6‐piperidinediones (+) 3a ‐(+) 3e is achieved by correlation of their CD spectra with the spectrum of R (+)‐glutethimide. It is shown that (+) 3a ‐(+) 3e possess R ‐configuration. The N ‐methyl compounds (+) 7a and (+) 7b , obtained by N ‐methylation of (+) 3a and (+) 3b , possess R ‐configuration, too, and so does (+) 3h which is formed by catalytic hydrogenation of (+) 3e . The absolute configuration of (+) 3g can be deduced from the configuration of the starting compound R (+)‐2‐ethyl‐2‐methylcyanoacetic acid: (+) 3g has S ‐configuration. Compounds (+) 3g and (+) 3f cause opposite Cotton effects. Thus, (+) 3f has R ‐configuration. The hitherto unknown configuration of (−)‐2‐ethyl‐2‐propylcyanoacetic acid, from which R (+)‐ 3f is obtained, can be deduced to be S .