2- Oxaadamantane

Following this preparation of 39 it is subjected to oxymercuration with mercury acetate and sodium chloride to give 4,8-bischloromercury-substi-tuted 2-oxaadamantane (107). Subsequent reduction with sodium borohy-dride yields 104.134,136... 

Another approach is based on the electrophilic halogenation of 39 in the presence of water, affording 4,8-dibromo-2-oxaadamantane (108) in 40.6% yield. Boiling 108 with Raney nickel in methanol yields 104.137,138 4,8-Dihydroxy-2-oxaadamantane (109) is obtained by performic acid oxidation of 39.137... 

The monomethylene ketone (35), actually a synthetic precursor of 31 as shown by the 34 -> 35 -> 31 conversion, is convertible to 2-oxaadamantane... 

Stepanov et a/.143,144 report the ring opening of the monoxide (116) to several 2-oxaadamantane derivatives, where 116 is readily obtained by perbenzoic acid oxidation of 35. Treatment of 116 under various conditions yields different products. Thus, with aqueous acid it yields l-hydroxy-3-hydroxymethyl-2-oxaadamantane (117), with alcohols (R = CH3, C2H5) in acidic or basic media 1-alkoxy-substituted (118), and with hydrochloric acid l-chloro-3-hydroxymethyl-2-oxaadamantane(119). l-Methyl-2-oxaadaman-tane (120) is prepared by LAH reduction of the carbonyl group in 35 to alcohol 121 and subsequent cyclization with acid.140,142... 

Lithium aluminum hydride reduction of 31 in the presence of benzylamine affords a 70% yield of l-benzylamino-2-oxaadamantane.154 This approach is patented as a general method for the preparation of N-substituted 2-oxa-adamantyl-l-amines.155 Transannular cyclization of 31 or 35 in the presence... 

Oxaadamantane and its derivatives are molecules of considerable interest to chemists and biologists, but until recently there was no convenient route to such compounds. Such a route has now been discovered, starting from the readily accessible 2-hydroxy-2-methyladamantane 1. Thus, oxidation of 1 by trifluoroperacetic acid in TFA at 20°C for one hour gave a mixture (actual yield not given merely described as "a good yield") of three products oxaadamantane 2 (56%), exo-4-hydroxy-2-oxaadamantane 3 (40%) and the lactone 4 (4%). 

Majerski, K.M. Kragol, G., Design, synthesis and cation-binding properties of novel adaman-tane and 2-oxaadamantane-containing crown ethers, Tetrahedron. 2001, 57, 449 157... 

Methyl-6-dichloromethyl-2-oxaadamantane (prepn. s. 329) hydrogenated ca. 2.5 hrs. with Raney-Ni in methanol containing NaOH until Hg-uptake ceases crude 6,6-dimethyl-2-oxaadamantane. Y 85%. H. Stetter and J. Mayer, B. 02, 2664 (1959). 

Osniic acid s. Osmium tetroxide Osmium tetroxide OG IPCG 2-Oxaadamantanes 16, 329... 

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