Selective functionalization of a resorcin[6]arene

The Mannich-type condensation of hexaethylresorcin[6]arene with achiral primary amines results in S6-symmetrical hexadihydro-1,3-oxazine derivatives, which are mesoforms. The reaction with individual enantiomers of α-phenylethylamine leads to C3-symmetrical enantiomeric hexaoxazines, which crystallize from reaction mixtures in an analytically pure form.