Adamantane

The chemical formula for adamantane: C10H16

Adamantane itself enjoys few applications since it is merely an unfunctionalized hydrocarbon. It is used in some dry etching masks and polymer formulations.
 * Uses:**

In solid-state NMR spectroscopy, adamantane is a common standard for chemical shift referencing. In dye lasers, adamantane may be used to extend the life of the gain medium; it cannot bephotoionized under atmosphere because its absorption bands lie in the vacuum-ultraviolet region of the spectrum. Photoionization energies have been determined for adamantane as well as for several bigger diamondoids.

This is the building block for a diamond and is almost indestructible. It even gets its name from the Greek work ADAMAS which means "indestructible".
 * Facts:**

The discovery of adamantane in petroleum in 1933 launched a new chemistry field studying the synthesis and properties of polyhedral organic compounds. Adamantane derivatives have found practical application as drugs, polymeric materials and thermally stable lubricants.

The possibility of the existence of a hydrocarbon with the C10H16 formula and diamond-like structure of the molecule was suggested by H. Decker at a conference in 1924. Decker called this molecule **decaterpene** and was surprised that it had not been synthesized yet. The first attempt of laboratory synthesis was made by German chemist Hans Meerwein in 1924 using reaction of formaldehyde with diethyl malonate in the presence of piper dine. Instead of adamantane, Meerwein obtained 1,3,5,7-tetracarbomethoxybicyclo[3.3.1]nonane-2,6-dione. This compound was later named Meerwein's ester and used in the syntheses of adamantane and its derivatives. Later, another German chemist D. Bottger tried to obtain adamantane using Meerwein's ester as precursor. However, the product, tricyclo-[3.3.1.13,7] decane ring system, was again an adamantane derivative.

Warning: Admantane will irritate skin and eyes if swallowed. Try to minimize exposure completely.



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 * Adamantane Property ||
 * ||  || mp : || 209-212 °C (subl.)(lit.) ||   ||
 * || density : || 1,07 g/cm3 ||  ||
 * || Merck : || 14,149 ||  ||
 * || BRN : || 1901173 ||  ||
 * || Stability:: || Stable. Combustible. Incompatible with strong oxidizing agents. ||  ||
 * || CAS DataBase Reference: || 281-23-2(CAS DataBase Reference) ||  ||
 * || NIST Chemistry Reference: || [|Adamantane(281-23-2)] ||  ||
 * || EPA Substance Registry System: || [|Tricyclo[3.3.1.13, 7decane(281-23-2)]] ||  ||

=High Levels of Adamantane Resistance Among Influenza A (H3N2) Viruses and Interim Guidelines for Use of Antiviral Agents --- United States, 2005--06 Influenza Season=

//On January 17, this report was posted as an// MMWR Dispatch //on the// MMWR //website// ([]). An estimated 200,000 persons are hospitalized each year and 36,000 persons die from complications of influenza in the United States (//1,2//). The cornerstone of influenza prevention is annual vaccination. However, antiviral drugs are an important adjunct to vaccination for influenza prevention and control. Two classes of antiviral medications are available currently: adamantanes or M2 ion channel inhibitors (i.e., amantadine and rimantadine) and neuraminidase inhibitors (i.e., oseltamivir and zanamivir). The adamantanes are active against only influenza A viruses and are used for both treatment and chemoprophylaxis of influenza A, whereas the neuraminidase inhibitors are active against both influenza A and B viruses. Zanamivir is not approved for chemoprophylaxis of influenza in the United States. This report describes new findings regarding the resistance to adamantanes of influenza A viruses currently circulating in the United States and provides interim recommendations that these drugs not be used during the remainder of the 2005--06 influenza season. Amantadine also is used to treat symptoms of Parkinson disease and may continue to be used for this indication. Resistance of influenza A viruses to adamantanes can occur spontaneously or emerge rapidly during treatment (//3//). A single point mutation in the codons for amino acids at positions 26, 27, 30, 31, or 34 of the M2 protein can confer cross-resistance to both amantadine and rimantadine (//4//). Neither replication, transmission, nor virulence of adamantane-resistant influenza A viruses are impaired by the point mutations conferring resistance (//5//). A recent report on the global prevalence of adamantane-resistant influenza A viruses indicated a significant increase of drug resistance, from 1.8% during the 2001--02 influenza season to 12.3% during the 2003--04 season (//4//). In the United States, the frequency of adamantane resistance increased from 1.9% during the 2003--04 influenza season to 11% during the 2004--05 season (CDC, unpublished data, 2005). In contrast to adamantane resistance, neuraminidase inhibitor resistance remains rare worldwide (//6//). The World Health Organization (WHO) Collaborating Laboratories and National Respiratory and Enteric Virus Surveillance System (NREVSS) laboratories in the United States submit influenza isolates to CDC as part of routine virologic surveillance. A subset of these isolates is further characterized at CDC, which includes testing for antiviral susceptibility. Although isolates are submitted by all U.S. states and territories, they are not necessarily a representative sample of all influenza viruses circulating in the United States. Since the beginning of the 2005--06 influenza surveillance season, WHO and NREVSS laboratories have tested a total of 38,932 specimens for influenza viruses; 1,557 (4.0%) tested positive. Among the 1,557 influenza viruses, 1,499 (96.3%) were influenza A viruses, and 58 (3.7%) were influenza B viruses. A total of 765 (51.0%) of the 1,499 influenza A viruses have been subtyped; 760 (99.3%) were influenza A (H3N2) viruses, and five (0.7%) were influenza A (H1N1) viruses. During October 1, 2005--January 14, 2006, a total of 123 influenza A viruses collected from 23 states were tested at CDC for adamantane resistance. Among the 120 influenza A (H3N2) viruses tested, 109 (91%) demonstrated the S31N substitution in the M2 protein that confers resistance to amantadine and rimantadine. Conventional sequencing on a subset of 20 viruses confirmed this substitution. Among the three influenza A (H1N1) viruses tested, none contained any mutations associated with resistance. As of January 14, all U.S. influenza viruses screened for antiviral resistance at CDC had demonstrated susceptibility to neuraminidase inhibitors. Procedures for virus propagation, RNA extraction, and pyrosequencing for adamantane resistance have been described previously (//4//).