Convenient and highly efficient chromatographic resolution of BINOL and of 6,6′-dibromo-BINOL via N(α)-Boc-tryptophan esters
作者:Bhavesh M. Panchal、Cathy Einhorn、Jacques Einhorn
DOI:10.1016/s0040-4039(02)02268-2
日期:2002.12
Racemic [1,1′]binaphthalenyl-2,2′-diol (BINOL, (±)-1) has been esterified with various commercially available N-protected-l-amino acids, giving the corresponding diastereomeric esters. Their TLC separation factors were highly dependent on the amino acid pattern. Diesters of (±)-1 and N(α)-Boc-tryptophan (3a) showed unusually large separation factors, which allowed their efficient separation by simple