Jm. Smith et al., NMR AND MOLECULAR MECHANICS STUDIES OF THE CONFORMATIONAL DYNAMICS OFTRICYCLO[3.3.3.03,7]UNDECANE DERIVATIVES, Tetrahedron letters, 34(38), 1993, pp. 5991-5994
Dynamic NMR studies and molecular mechanics calculations both indicate
that twisting about the C3-C-7 bond facilitates flipping of the trime
thylene bridge in the tricyclo[3.3.3.0(3,7)]undecane ring system.