Synthesis and chemistry of homocubanes, bishomocubanes, and trishomocubanes

Cage-Shaped Molecules Derived by Applying the Edge Strategy to a Cubane Skeleton

“…The present article is devoted to the application of the edge strategy to a cubane skeleton of o h -symmetry, because cubane itself [7] and its derivatives such as basketane [8,9] and D 3 -trishomocubane [10][11][12] have attracted the interest of synthetic organic chemists, as summarized in a review [13]. Although systematic discussions based on D 3 -twisted bicyclo[2.2.2]octane molecular framework as a common structural unit have appeared [14], the edge strategy applied to a cubane skeleton aims at providing more quantitative perspectives.…”

Structural effects on the thermochemical properties of cycloalkanones. III. Enthalpy of combustion, vapour pressures, and enthalpy of sublimation, and standard enthalpy of formation in the gaseous phase of pentacyclo[5.4.0.02,6.03,10.05,9]undecane-8,11-dione

“…(1)(2)(3)(4) We have now initiated the study of the strain effects on cyclic carbonyl compounds. (5,6) In this work, we have investigated the thermochemical properties of pentacyclo [5.4.0.0 2,6 .0 3,10 .0 5,9 ]undecane-8,11-dione. Polycyclic cage compounds are man-made products (7) which have been applied to a variety of problems ranging from synthetic and mechanistic studies to materials science, and pharmaceutical and medicinal applications.…”

“…(8)(9)(10) Most saturated cage molecules have considerable strain energy as evidenced by the fact that they contain unusually long framework carbon-carbon σ -bonds; they also contain unusual C-C-C bond angles that deviate significantly from π; they possess unusually large enthalpies of combustion, and, from this point of view, they have substantially positive enthalpies of formation when compared with non-strained systems. (10) In the field of cage compounds, the chemistry of pentacyclo[5.4.0.0 2,6 .0 3,10 .0 5,9 ]undecane (PCUD) derivatives has been the subject of recent studies, (8,9,11,12) and the rigid and highly symmetrical 8,11-diketone (PCUD-8,11-dione, A, see figure 1) has been used as a starting material in the preparation of a number of polyquinane derivatives (8,9,13) (hirsutene, coriolin, and capnellene, for example), and as a mechanistic probe to study long-range interactions between non-conjugated π-systems, which can be propagated by steric or bond-bond interactions, or both. (14)(15)(16)(17)(18) In addition, derivatives of A display biological activity as antivirals or, more importantly, calcium antagonists.…”

“…This rather unusual feature makes the determination of the energetics of the carbonyl-carbonyl interaction in A a particularly appealing objective. For all the reasons pointed out above, we have studied the thermochemical properties of pentacyclo[5.4.0.0 2,6 .0 3,10 .0 5,9 ]undecane-8,11-dione in this work.…”

A Novel Synthetic Method of Endo-pentacyclo[5.4.0.02,6.03,10.05,9]- undecane-8-ol

“…常见的笼状化合物包括: 金刚烷、 立方烷和五环 ]十一烷(简称 PCU, 密度 ρ＝ 1.24 g/cm 3 ) [4] . Marchand 等在 1974 年首次合成出五环 [5.4.0.0 2,6 .0 3,10 .0 5,9 ]十一烷(PCU) [5] , PCU 的燃烧热值能达 到 51.66 MJ/L, 远高于现有的液体碳氢燃料, 但该化合 物具有较强的挥发性, 影响到其用作燃料的实际应用.…”