Crystal structures of two fused cyclic compounds, 4-(methyl(sulfonyl)methoxy-2-vinyl)-2S*,3aR*,4S*,5,7aS*-(hexahydro-1H-indan-3a-yl)methylmethanesulfonate (1) and (1S*,2S*,4S*,7R*)-7-(dimethyl(phenyl)silyl)-4′,5′-dihydro-2′H-spiro[bicyclo[2.2.1]hept[5]ene-2,3′-furan]-2′-one (2), have been solved from laboratory X-ray powder diffraction data using direct space approach and refined following the Rietveld method. In the absence of strong hydrogen bond donating groups, the crystal packing of 1 and 2 exhibits C–H ⋯ O hydrogen bonds and C–H ⋯ π interactions forming two-dimensional (2D) supramolecular network. The nature of intermolecular interactions in 1 and 2 has been analyzed through the Hirshfeld surface and 2D fingerprint plots. The density functional theory optimized molecular geometries in 1 and 2 agree closely with those obtained from the crystallographic study. Hirshfeld surface analysis of 1, 2 and a few related fused carbocyclic and carbooxacyclic systems retrieved from the Cambridge Structural Database indicates that about 85% of Hirshfeld surface area in these compounds are because of H ⋯ H and O ⋯ H interactions.