Adamantane dicarboxylic acid

Perfluorodimethyladamantane is prepared from adamantane dicarboxylic acid by treatment with sulfur tetrafluoride followed by energetic fluorination with cobalt trifluoride over two temperature ranges [S] (equation 15)... 

Adamantane dicarboxylic acid [39269-10-8] M 224.3, m 276, 276-278, 279. Dissolve in aq NaOH, treat with charcoal, filter and acidify with dilute HCl. Recryst from MeOH. [B 93 1366 7960]. 

The present strategy was successfully applied to the preparation of adamantane-dicarboxylic acid, which is an interesting monomer in polymer chemistry, through a stepwise procedure (Eq. (6.24)), although the dicarboxylic acid is difficult to obtain by conventional methods. Similarly, 1,3-dimethyladamantaneand mdo-tricyclo[5.2.1.0] decane were carboxylated to the respective mono- and dicarboxylic acids. 

Starting from adamantane and tert. butanol as hydride ion acceptor adamantane carboxylic acid is formed even in 80 % yield. An 85 % yield of adamantane dicarboxylic acid is reported in a patent of DuPont [793]. 

Furthermore, di- and polychlorination are much less prevalent. Dicarboxylic acids are predominantly chlorinated in the middle of the chain,99 and adamantane and bicy-clo[2.2.2]octane at the bridgeheads100 by this procedure. The reasons for the high to - 1 specificity are not clearly understood.101 Alkyl bromides can be regioselectively chlorinated... 

An important goal is, therefore, to develop effective methods for catalytic oxidations with dioxygen, under mild conditions in the liquid phase. Two substrates which are often chosen as models for alkane oxidations are cyclohexane and adamantane. Cyclohexane is of immense industrial importance as its oxidation products - cyclohexanone and adipic acid - are the raw materials for the manufacture of nylon-6 and nylon-6,6. Adamantane is an interesting substrate as the ratio of oxidation at the secondary versus the tertiary C-H bonds is used as a measure of radical versus nonradical oxidation pathways. Industrial processes for the oxidation of cyclohexane, to a mixture of cyclohexanol and cyclohexanone, generally involve low conversions (under 10%). Even at such low conversions, selectivities are modest (70-80%) and substantial amounts of overoxidation products, mostly dicarboxylic acids, are formed. 

BrCeH4-CF2-CFaPh (vii) adamantano4 rboxylic or -dicarboxylic acids-t-SF4 - trifluoromethylated adamantanes - [replacement of bridgehead hydrogen by fluorine also occurs e.g., conditions for the conversion of adamantane-1 carboxylic acid into either a 15 1 mixture of l-(trifluoromethyl)adamantane and... 

C—C bond reorganization in confined space is also possible with sp -hybridized carbon-based molecules. Adamantane was confined in DWCNTs forming linear adamantine assanbUes [188]. The annealing of the sp -hybridized nanostructures under vacuum at temperatures higher than 500°C convert the adamantine into carbon chains inside the CNTs however, the introduction of H2 during the annealing step suppressed their formation. Similarly, diamond nanowires formed inside DWCNTs from encapsulated diamantane dicarboxylic acid [189]. 

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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