Crystal structures of (12E)-12-(4-benzyl-idene)-7,7,16-trimethyl-3-(4-methyl-phen-yl)-1-oxa-16-aza-tetra-cyclo-[11.2.1.0(2,11).0(4,9)]hexa-deca-2(11),4(9)-dien-5-one and (12E)-12-(4-bromo-benzyl-idene)-73-(4-bromo-phen-yl)-,7,16-trimethyl-10-oxa-16-aza-tetra-cyclo-[11.2.1.0(2,11).0(4,9)]hexa-deca-2(11),4(9)-dien-5-one.

The title compounds, C(32)H(35)NO(2), (I), and C(30)H(29)Br(2)NO(2), (II), differ by the presence of a bromine atom instead of a methyl atom in the para position of two benzene rings of compound (II). The two compounds have a structural overlap r.m.s. deviation of 0.27†à . The pyran and seven-membered cyclo-heptene rings in both structures adopt boat and boat-sofa conformations, respectively. Intra- and inter-molecular C-H⋯O hydrogen bonds are responsible for the consolidation of the crystal packing of both mol-ecules. In addition to this, weak C-H⋯π inter-actions are also observed. The inter-molecular inter-actions were qu-anti-fied and analysed using Hirshfeld surface analysis.