The first example of the stereoselective synthesis and crystal structure of a spirobicycloquinazolinone based on (–)-fenchone and anthranilamide

Abstract

The possibility of a single-stage solvent-free stereoselective synthesis of a spirocyclic compound from the natural bicyclic monoterpenoid (−)-fenchone and anthranilamide has been shown for the first time. The molecular and crystal structure of (1R,2S,4S)-1,3,3-trimethyl-1′H-spiro[bicyclo[2.2.1]heptane-2,2′-quinazolin]-4′(3′H)-one, C17H22N2O, was established by X-ray diffraction though the chirality was assumed via the known reactant connectivity and 1H and 13C NMR spectroscopy. It has shown that in the molecule, for steric reasons, there is an elongation of the Me2C—C(N)N bond to 1.603 (5) Å. The formation of dimers via N—H...O=C hydrogen bonds with an interaction energy of 93.30 kJ mol−1 and through cavities (33.7% of the unit-cell volume) was established in the packing of the molecules. There are no π-stacking interactions in the structure.