(±)-(1SR,8RS,10RS)-9,9,10-Tribromo­tricyclo­[6.2.1.0^2,7]undeca-2,4,6-triene

The title compound, C₁₁H₉Br₃, consists of a norbornane skeleton, composed of two five-membered rings in envelope conformations and a six-membered ring with three Br atoms held in a boat conformation by a bridging methyl­ene group, which constitutes a bicyclo­[2.2.1]heptane system, having a benzene ring fused on one side. The repulsive interactions between the Br atoms affect the topology of the norbornane skeleton.

4′,4′,6′,6′-Tetra­chloro-3-(4,6-dimethyl­pyridin-2-yl)-3,4-dihydro­spiro­[1,3,2-benzoxaza­phosphinine-2,2′-(2λ⁵,4λ⁵,6λ⁵-cyclo­triphosphazene)]

The title compound, C₁₄H₁₄Cl₄N₅OP₃, is a phosphazene derivative with a bulky substituent attached through a spiro junction. The C₃NPO ring at the spiro junction has a twist–boat conformation, while the phosphazene ring has a flattened-boat conformation. The P_spiro atom is likely to be stereogenic.

7,11-(Butane-1,4-diyldioxydi-o-phenyl­enedimethyl­ene)-6,6-dichloro-4,4-bis­(pyrrolidin-1-yl)-2λ⁵,4λ⁵,6λ⁵-triphosphaza-1,3,5,7,11-penta­aza­spiro­[5.5]undeca-1,3,5-triene

The title compound, C₂₉H₄₂Cl₂N₇O₂P₃, is a phosphazene derivative with a bulky substituent attached through a spiro junction with two pyrrolidine rings. The six-membered C₃N₂P ring has a chair conformation, while the phosphazene ring has a slight envelope conformation. The two N atoms in the C₃N₂P ring are likely to be stereogenic.

(1SR,2SR,3SR,10SR,12RS,13RS,14RS,17SR)-13-Hydr­oxy-11-oxapenta­cyclo­[8.7.0.0^2,14.0^4,9.0^12,17]hepta­deca-4,6,8-trien-3-yl 4-chloro­benzoate

In the title compound, C₂₃H₂₁ClO₄, the bicyclic system has approximate D₃ symmetry and the four non-planar six-membered rings adopt boat conformations. Intra- and inter­molecular hydrogen bonds are effective in stabilizing the crystal structure.