K. K. Mak
Nov 1, 2004
Citations
0
Influential Citations
6
Citations
Journal
Journal of Chemical Education
Abstract
The synthesis and resolution of the atropisomeric 1,1'-bi-2-naphthol illustrates several important concepts in organic chemistry and serves as a good experiment for organic chemistry laboratory course of intermediate to advanced levels. Racemic 1,1'-bi-2-naphthol is synthesized by the oxidative coupling of 2-naphthol and is resolved into the enantiopure form by the selective inclusion compound formation of the R enantiomer with (−)-N-benzylcinchonidinium chloride. The enantiomeric excess of the products are determined by chiral HPLC. The naphthol unit of 1,1'-bi-2-naphthol is composed of a benzene and a phenol fused together. Both 1H and 13C NMR spectra show complicated and overlapping signals in the aromatic region and complete signal assignment is extremely difficult. Unambiguous signal assignment is made possible with the help of various 2-D NMR techniques such as COSY, HMQC, and COLOC. It serves as an advanced exercise for spectroscopic structural identification of organic compounds.