Rings s. a. Adamantanes

Rings s. a. Adamantanes, Alcohols, cyclic, Hetero-cyclics, Isocyclics, Ketones, cyclic, Macrocyclics, Poly-cyclics, Propellanes -, condensed highly condensed s. Cage compds. 

X-Ray structure analysis of 14a, 15a, and 15b has established the central adamantane cage which is characteristic of the unsolvated triamides [6, 8], Whereas there is little appreciable interaction between the periphery of the molecules in the structures of the t-butyl substituted species 15a and 15b, the two-coordinate Li-atoms are "internally solvated" by the phenyl groups in the chiral triamide 14a (Fig. 3). The orientation of the aryl rings towards the puckered six-membered (LiN)s-ring and the short contact between Li and C7 indicates a direct interaction between the metal atoms and the periphery. 

Restriction among the great number of possible dihetero-tricyclodecanes to such with a carbocyclic 8-membered ring (cyclooctane) as basic skeleton, which is crosswise bridged by two heteroatoms, and restriction to 5-, 6- and 7-membered heterocyclic rings, isomeric dihetero-tricyclodecanes of the following five different stmctural types are possible 2,6-dihetero-adamantane (G 7 ) 2,7-dihetero-isotwistane (G 2,7-dihetero-twistane (G S) 2,8-dihetero-homotwistbrendane (G 4) and 2,6-dihetero-tricyclo[3.3.2.0 Jdecane (G 5) . 

Supramolecular assemblies/architectures represent an alternative approach to electrically connecting redox proteins with electrodes. For example, bis-bipyridinium cyclophane has been threaded onto a molecular wire assembled on an electrode by the formation of an intermediary pdonor-acceptor bond with the bis-imine-benzene site of the molecular wire [4]. The wire was then stoppered by an adamantane stopper unit to form a supramolecular assembly. The charged cyclophane could then be moved along the wire by electrochemi-cally changing its oxidation state. Reduction of the cyclophane to the bis-radical cation removed the electron acceptor properties of the threaded ring, and the reduced acceptor was electrostatically attracted by the electrode. This resulted in translocation of the reduced cyclophane to the electrode with a rate constant corresponding to k = 320 s. Oxidation of the reduced cyclophane reversed the direction of movement. 

Hyperflorin, an antibiotic isolated from St. John s wort Hypericum perforatum L.), has been found on the basis of chemical and spectroscopic evidence to possess structure (639). ° A review on the conformational analysis of bicyclo[3,3,l]nonanes has appeared,and the conformations of l,5-disubstituted-3,7-dimethyIenebicyclo-[3,3,l]nonane derivatives have been shown, on the basis of lanthanide-induced n.m.r. shifts, to be predominantly in the double-chair form. In a notable paper that contains a wealth of information pertinent to adamantane synthesis, it has been reported that bicyclo[3,3,l]nonane-3,7-dicarboxylic acid, its dimethyl ester, and various derivatives exist mainly in the chair-boat conformation. The synthetic entry to these systems is illustrated for the above diester (643) in which the starting point is adamantanone (640) thus, ring expansion with diazomethane followed by SeOj oxidation gave the a-diketone (641) which was cleaved with periodate to give the diacid (642). Esterification using diazomethane gave (643) which exists, as does the diacid, as... 

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