318233-91-9Relevant academic research and scientific papers
A chiral axis due to an acyclic imide-Ar bond: A study of steric effects of acyl groups on racemization
Kondo, Kazuhiro,Iida, Takeko,Fujita, Hiroko,Suzuki, Tomoko,Yamaguchi, Kentaro,Murakami, Yasuoki
, p. 8883 - 8891 (2007/10/03)
Studies on the racemization in a series of optically active compounds 3a-e, including the steric effect of their acyl groups, are described. The first example of optically active compounds 3c and 3d, which possess axial chirality based on an acyclic imide-Ar bond, has been reported. A quite interesting result has been revealed, namely, that 3a bearing a bulky acyl group rather than a relatively small one racemized more easily. To explain this observed phenomenon, 13C NMR experiments and the reaction with benzylamine of 3a-e were undertaken. These results suggested that the t-BuCO-N bond in 3a which racemized easily, is more twisted, compared with the RCO-N bonds in 3b-e which are relatively stable to racemization. Furthermore, the absolute configuration of 3b and 3c has been determined to be R by the CD spectrum and the X-ray crystallographic analysis of racemic 3f has been accomplished. (C) 2000 Published by Elsevier Science Ltd.
