0000000000480663
AUTHOR
Volker Bo¨hmer
One-step synthesis of resorcarene dimers composed of two tetra-benzoxazine units
Abstract The condensation of resorcarene 1 with ethylenediamine and an excess of formaldehyde gives, under high dilution conditions, in up to 15% yield the octa-benzoxazine dimer 2 in which two molecules of 1 are connected by four bridges. The structure of 2 has been confirmed by 1 H NMR spectra and MALDI-TOF mass spectra and by hydrolysis of the oxazine rings yielding the secondary amine 3 .
Resolution of inherently chiral resorcarene derivatives by enantioselective HPLC
Abstract The HPLC enantiomeric resolution of five inherently chiral tetrabenzoxazine derivatives of resorcarenes has been achieved by HPLC using Whelk-Ol and in one case Chiralpak AD as stationary phases. Enantiomeric separation was only observed in a very narrow range of mobile phase compositions. On-column enantiomeric interconversion of a racemic compound with a typical plateau-like elution profile was observed using a Chiralpak AD column