STRUCTURES OF 4 TRICYCLO[3.3.0.0(3,7)]OCTANES AND A 4-OXATETRACYCLO[4.2.1.0(2,5).0(3,7)]NONANE DERIVATIVE

N,N-Dimethyl-6-methylenetricyclo-[3.3.0.0(3,7)]octane-2-carboxamide (1), C12H17NO, M(r) = 191.27, monoclinic, P2(1)/c, a = 11.213 (2), b = 6.168 (1), c = 15.268 (3) angstrom, beta = 95.07 (1)-degrees, V = 1051.8 (6) angstrom3, Z = 4, D(x) = 1.21 Mg m-3, mu = 0.071 mm-1, F(000) = 416, T = 298K, final R = 0.047 for 1782 observed reflections. 4,6-Diisopropyl-idenetricyclo[3.3.0.0(3,7)]octan-2-one (2), C14H18O, M(r) = 202.30, monoclinic, P2(1)/n, a = 9.532 (1), b = 9.218 (1), c = 13.496 (2) angstrom, beta = 97.57 (1)-degrees, V = 1175.5 (5) angstrom3, Z = 4, D(x) = 1.14 Mg m-3, mu = 0.065 mm-1, F(000) = 440, T = 208 K, final R= 0.041 for 2244 observed reflections. 4,6,8-Triisopro-pylidenetricyclo[3.3 .0.0(3,7)]octan-2-ol (3), C17H24O, M(r) = 244.38, monoclinic, P2(1)/c, a = 8.618 (1), b = 22.054 (5), c = 7.871 (1) angstrom, beta = 93.24 (1)-degrees, V = 1493.6 (7) angstrom3, Z = 4, D(x) = 1.09 Mg m-3, mu = 0.061 mm-1, F(000) = 536, T = 223 K, final R = 0.049 for 2211 observed reflections. 6,8-Diisopropyl-idenetricyclo[3.3.0. 0(3.7)]octane-2-spiro-1'-cyclopentane-4-one (4), C18H24O, M(r) = 256.39, monoclinic, P2(1)/c, a = 11.796 (3), b = 11.483 (2), c = 11.312 (2) angstrom, beta = 96.10 (2)-degrees, V = 1523.6 (7) angstrom3, z = 4, D(x) = 1.12 Mg m-3, mu = 0.062 mm-1, F(000) = 560, T = 223 K, final R = 0.047 for 2467 observed reflections. 3-Isopropyl-8,9-diisopropylidene-4-oxa-tetracyclo[4.2.1 0(2.5).0(3,7)]nonane (5), C17H24O, M(r) = 244.38, triclinic, P1BAR, a = 9.675 (2), b = 12.997 (2), c = 6.454 (1) angstrom, a = 91.14 (2), beta = 100.51 (2), gamma = 70.34 (2)-degrees, V = 750.7 (3) angstrom3, Z = 2, D(x) = 1.08 Mg m-3, mu = 0.060 mm-1, F(000) = 268, T = 295 K, final R = 0.046 for 2486 observed reflections. The radiation used for compounds (1) to (5) was Mo Kalpha, lambda = 0.7107 angstrom. The cage-like molecules are highly strained with the consequence that the C-C bridging bonds are distinctly lengthened to 1.606 (2)-1.621 (2) angstrom.