Attempted Resolution and Racemization of Beckmann‐Derived CTV‐Lactam and the Use of Chirabite‐AR® to Determine the Optical Purity of the Supramolecular Scaffold

Chirabite-AR was employed to differentiate enantiomers of the axially chiral cyclotriveratrylene (CTV)-derived macrocyclic lactam with baseline separation of most of the proton NMR resonances enabling enantiomeric purity determination of this supramolecular scaffold. Attachment of menthyloxy acetic acid as a chiral auxiliary to the CTV-Beckmann derived lactam afforded diastereomers that were enriched to a ratio of 87:13, as confirmed by both ¹ H NMR and single-crystal X-ray diffraction. Basic hydrolysis of the enriched diastereomeric mixture proceeded with rapid bowl inversion to yield racemic CTV-lactam as confirmed by Chirabite-AR NMR analysis. Density functional theory (DFT) calculations (M06 2X/6-31G*) were performed on the crown and saddle conformers of the CTV-lactam.