Synthesis, Crystal Structure Analysis and DFT Studies of Two Benzospirocyclic Ketones

Functionalized 3H-spiro[isobenzofuran-1,3′-isochroman] skeleton have been synthesized in our laboratory with high regioselectivity via palladium-catalyzed intermolecular tandem cycloaddition reactions. In this study, two benzospirocyclic derivatives 6′-methoxy-4′-methylene-3H-spiro[isobenzofuran-1,3′-isochromane] and 6-fluoro-4-methylene-3′H-spiro[isochromane-3,1′-naphtho[2,3-c]furan] were selected for crystallographic analysis, and structural validation was performed by FTIR, ¹H NMR,¹³C NMR and MS. In addition, the molecular structure was calculated by density function theory (DFT) and compared with X-ray derivative data. The analysis of the conformation also showed that the molecular structure obtained by X-ray diffraction analysis was the same as the optimized molecular structure obtained by DFT. Moreover, the molecular electrostatic sites and frontier molecular orbitals of the title compounds were investigated further using DFT, which has revealed the molecular structural features, conformations and some special physicochemical characters of the title compounds.