Mode of molecular recognition during optical resolution: A structural study of the molecular complex involving both 3-hydroxypyrrolidines and (R,R)-(−)-trans-bis(hydroxydiphenylmethyl)-1,4- dioxaspiro[4,5]decane
✍ Scribed by Kazuyoshi Nishikawa; Harumichi Tsukada; Satoshi Abe; Maki Kishimoto; Noritake Yasuoka
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 203 KB
- Volume
- 11
- Category
- Article
- ISSN
- 0899-0042
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✦ Synopsis
Optical resolution of the racemates of 3-hydroxypyrrolidine (1), N-benzyl-3-hydroxypyrrolidine (2) and N-ethyl-3-hydroxypyrrolidine (3) was carried out using an optically active host molecule, (R,R)-(-)-trans-bis(hydroxydiphenylmethyl)-1,4dioxaspiro [4,5]decane (4). The host 4 could involve the (S)-enantiomer of 2 (2S) more efficiently than the (R)-enantiomer (2R). In the 13 C-NMR spectra, both 2 and 3 showed split signals of some carbon position in the presence of 4. This result indicated that 4 recognized each enantiomer in solution. The results of the optical resolution and the 13 C-NMR study suggested that a substituent group on the nitrogen atom (N-atom) played an important role in the enantioselective complexation. An X-ray crystal analysis showed that hydrogen bonds in a molecular complex involving both 2S and 4 played an important role in the complexation. The van der Waals contacts between the hydrophobic sites of 2S or 4 seemed to stabilize the entire crystal structure.