Preparation of New Chiral Di-t-Butyl-, Diphenyl- and Dimethyl- Substituted Pyridino-18-Crown-6 Ligands
Abstract
Three new chiral pyridino-18-crown-6 ligands containing either two t- butyl, two phenyl or two methyl substituents have been prepared. These ligands were prepared by reacting the appropriate chiral tetraethylene glycol with 2,6- pyridinedimethyl ditosylate to give 1, an oil, alpha-15.09 (c = 0.424, benzene); 2, melting point 66-67 C, alpha-128.9 (c = 0.34, benzene); 3, an oil alpha -22. 45 (c = 1.648, benzene). The starting chiral tetraethylene glycols (4-6) were prepared as shown in Scheme II. t-Butylethylene glycol needed to prepare the chiral di-t-butyltetraethylene glycol (4) was resolved through its hydrogen phthlate ester and using brucine as the resolving agent. Complexation of the (R) - and (S)- forms of alpha-(1-naphthyl)ethylammonium perchlorate by chiral ligands 2 and 3 have been studied by 1H NMR methods in CD3OD. Ligand (R,R)-2 exhibited modest chiral recognition for the (S)- form of the salt over the (R)- form. However, ligand (R,R)-3 exhibited little or no chiral recognition for the enantiomers of the ammonium salt. Keywords: Organic compounds, Enantiomers, Molecules, Molecular isomerism, Stereochemistry, Asymmetry.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 18, 1990
- Accession Number
- ADA221561
Entities
People
- C. Y. Zhu
- J. S. Bradshaw
- P. Huszthy
- Reed Izatt
Organizations
- Brigham Young University