Citation:
Abstract:
The 2:1 adduct of benzyne with 2-methylanisole is shown to have the bisbenzotricyclic structure 6,6a,11,11a-tetrahydro-5-methoxy-6-methyl-5,6,11-metheno-5H-benzo[a]fluorene by a single-crystal X-ray diffraction study (C20H18O: Pca2(1), a = 15.0497(17), b = 9.87783(11), c = 9.6846(11); Z = 4; 1672 data points, R, = 0.0325). This structure is compared to an unpublished crystal structure of the parent hydrocarbon 6,6a, 11, 11a-tetrahydro-5,6,11-metheno-5H-benzo[a]fluorene, C18H14. Both structures have also been computed by DFT methods at the B3LYP/6-311 (d,p) level of theory. Bond distances and angles between the solid-state measurements and gas-phase calculations are found to agree well; average deviations are well below 1%. The H-1 NMR spectra show surprisingly small (3)J(HH) couplings in the central tricyclic cage, but can be assigned using 2D spectroscopy.
Notes:
Times Cited: 1Bender, Christopher O. Boere, Rene T. Dibble, Peter W. McKay, Ryan T.