L- adamantane

Adamantane (A) and adamantan-4-one (B) were specifically hydroxylated at the quaternary C-1 by cytochrome P450j, to produce C and D. In contrast, the eukaryotic cytochrome P450lm2 formed in addition to the C-2 compound from adamantane, and both 5-hydroxy-adamantan-l-one (D) and the 4-a fi-hydroxyadamantan-l-one (E) from adamantan-4-one (Figure 3.18b) (White et al. 1984). 

Recently Togni et al. [19] focussed on the preparation of asymmetric dendrimer catalysts derived from ferrocenyl diphosphine ligands anchored to dendritic backbones constructed from benzene-1,3,5-tricarboxylic acid trichloride and adamantane-l,3,5,7-tetracarboxylic acid tetrachloride (e.g. 11, Scheme 11). In situ catalyst preparation by treatment of the dendritic ligands with [Rh(COD)2]BF4 afforded the cationic Rh-dendrimer, which was then used as a homogeneous catalyst in the hydrogenation reaction of, for example, dimethyl itaconate in MeOH. In all cases the measured enantioselectivity (98.0-98.7%) was nearly the same as observed for the ferrocenyl diphosphine (Josiphos) model compound (see Scheme 11). 

Kollner et al. (29) prepared a Josiphos derivative containing an amine functionality that was reacted with benzene-1,3,5-tricarboxylic acid trichloride (11) and adamantane-l,3,5,7-tetracarboxylic acid tetrachloride (12). The second generation of these two types of dendrimers (13 and 14) were synthesized convergently through esterification of benzene-1,3,5-tricarboxylic acid trichloride and adamantane-1,3,5,7-tetracarboxylic acid with a phenol bearing the Josiphos derivative in the 1,3 positions. The rhodium complexes of the dendrimers were used as chiral dendritic catalysts in the asymmetric hydrogenation of dimethyl itaconate in methanol (1 mol% catalyst, 1 bar H2 partial pressure). The enantioselectivities were only... 

Cis-RuClj(phen)3 is made as black crystals by reaction of RUCI3 with (phen). As CM-RuCl2(phen)3/aq. yO / BuOH or 1,2-dimethoxyethane it stereospecifically epoxidised oleic acid to 9, 10-epoxyoctadecanoic acid [833] The reagent cis-RuCljlphey /aq. Li(C10)/CH3Cl2 oxidised dipropylether to propylpropionate, tet-rahycfiopyran to 6-valerolactone, adamantane to adamantan-l-ol and adamantanone, and octan-2-ol to octan-2-one [834],... 

Bis-[l-adamantyl]-furazan-2-oxid zerfallt bereits in siedendem Tetrachlormethan zu Adamantan-l-ni-triloxid 5. 

Adamantanecarboxylic acids with a carboxylic group at a bridgehead position, e.g. adaman-tane-1-carboxylic acid (8),111 react with sulfur tetrafluoride in the conventional way giving high yields of the corresponding trifluoromethyl-substituted adamantanes. l-(Trifluoromethyl)-adamantane (9) can also be formed in one step from adamantane by treatment with a mixture of sulfur tetrafluoride, hydrogen fluoride and formic acid the latter serves as a source of carbon monoxide. The reaction is believed to proceed via carbonylation of an intermediate carbocat-... 

Trifluoromethyl)adamantan-l-amine (17) is obtained in 50% yield from 3-aminoadaman-lane-1-carboxylic acid.115... 

The only direct transformation of a hydroxy group to the corresponding fluoro compound has been described in the case of adamantan-l-ol (l).8... 

Desulfuration of thiols.2 Aromatic, benzylic, and aliphatic thiols are converted into hydrocarbons when heated in acetic acid with molybdenum carbonyl. The bridgehead adamantane-l-thiol is an exception and gives instead a thioester, RSCOCHj. Yields are 50-90%. The actual reagent is probably tetrakis(acetato)-dimolybdenum.3 Molybdenum carbonyl deposited on silica can also be used. 

A general mathematical treatment has recently been developed which enables the construction of a graphical representation of such rearrangements39 . This treatment has been applied to the rearrangement of tetrahydrodicyclopen-tadiene (2) to adamantane (l)40). Assuming that only 1,2-alkyl shifts are allowed and excluding steps which form either primary cations or unreasonably strained isomers, the intermediates which may be involved and the pathways by which they are interconverted are illustrated in Scheme 3 4° . At least 2,897 independent pathways for the conversion of 2 to 1 are possible40). 

The high yields and mild reaction conditions of each of these rearrangements to adamantane or 1-adamantanol constrast sharply with the low yields and relative severe reaction conditions required for the conversion of tetra-hydrodicyclopentadiene (2) to adamantane (l)4,4[Pg.16]

To a stirred solution of [4-(2-pyrimidinyl)piperazino]ethylamine (2.0 g, 0.01 mol) in 50 ml of methylene chloride, adamantane-l-carboxylic acid chloride (3.6 g, 0.018 mol) and triethylamine (2.9 g, 0.015 mol) were added. Stirring was continued at room temperature overnight. The methylene chloride solution was washed with water, dried over anhydrous sodium sulfate and evaporated under reduced pressure. The remaining residue was subjected to preparative HPLC. The residue was dissolved in ethyl acetate (10 ml) and subjected to flash chromatography using a 9 inch column of silica gel and ethyl acetate as the eluent. The N-[2-[4-(2-pyrimidinyl)-l-piperazinyl]ethyl]tricyclo[3.3.1.1(3,7)] decane-l-carboxamide was separated. 

A solution of 3-acetamino-adamantane-l-carboxylic acid (3.0 g) in 4 N sodium hydroxide (40 ml) was refluxed for 5 h. After cooling, the pH of the solution was adjusted to 7 with acetic acid. The crystalline precipitate was filtered off, washed with ethanol and dried to yield 2.20 g of the desired compound, melting point over 330°C. In order to purify the compound, 2.0 g of it was suspended in water (10 ml), 4 N NaOH (2 ml) was added, and the resulting solution filtered through a filter aid known under the registered trademark Dicalite. The filtrate was adjusted to a pH of 6.5 with acetic acid. The resulting crystalline precipitate was filtered off, washed with a little water followed by alcohol, and dried to yield 1.55 g of pure 3-amino-adamantane-l-carboxylic acid. 

A suspension of betamethasone (740.0 mg) in dioxan (20 ml) was treated with adamantane carboxylic acid (1.96 g) and trifluorcacetic anhydride (0.75 ml). The mixture was stirred at room temperature for 23 h during which time the steroid completely dissolved. Addition of sodium bicarbonate (2.0 g) and water gave a waxy semi-solid which was separated from the supernatant liquid by decantation. Water and a little methanol were added to the solid and the resulting granular material was removed by filtration and washed well with water. Fractional crystallization from methanol afforded adamantane carboxylic anhydride as the less soluble component and betamethasone 21-adamantane-l -carboxylate as the more soluble component. 

A solution of betamethasone (1.0 g) in dry tetrahydrofuran (40 ml) was treated with adamantane carbonyl chloride (about 2.2 equivalents) in dry tetrahydrofuran (5 ml) and then pyridine (0.8 ml) was added. The mixture was refluxed for 6 h and then most of the solvent was boiled off and the residue extracted with chloroform to afford a froth. The ether soluble portion of this froth was dissolved in chloroform and extracted repeatedly with dilute sodium bicarbonate solution. Evaporation of the chloroform layer gave a froth which was further purified by chromatography and crystallisation from chloroform-petroleum ether to yield betamethasone 21-adamantane-l -carboxylate melting point 256°-259°C (dec.). 

In the past decade, there has appeared only one report, which can be classified under this heading, on the monodeoxygenation of spiro-adamantane-l,2-dioxetanes induced by catalytic amounts of tris-(2,4-dibromophenyl)-aminium hexachloroantimonate <1998T6939>. An electron-transfer mechanism from the aminium salt has been proposed for the observed formation of various ketones. Reports citing the electrophilic ring opening of dioxetanes by boron trifluoride, trifluoroacetic acid, and various other Lewis acids have been summarized in CHEC-II(1996) <1996CHEC-II(1B)1041>. 

The condensation of thiophenols with ethyl aroylacetates is brought about by heating in PPA and yields 2-arylthiochromones 522 (Equation 182) <1996JME1975>. 2-Adamantan-l-ylthiochromone is obtained in like manner from ethyl 3-(l-adamantyl)-3-oxopropanoate <2004JME4268>. 

Nayyar A, Monga V, Malde A et al (2007) Synthesis, anti-tuberculosis activity, and 3D-QSAR study of 4-(adamantan-l-yl)-2-substituted quinolines. Bioorg Med Chem 15 626-640... 

Bott (1969 a, b), by allowing adamantan-l-ol and acetylene to react in 95% Hj5S04 at 4-7°, observed the formation of aldehyde 26 as the main product, together with ketones 25 and 27. The yields of ketone 25... 

From adamantan-l-ol and acetylene in 90% H2S04 Kell and McQuillin (1969) obtained exclusively the aldehyde 26 and ketone 27. Addition to substituted adamantyl acetylenes, AdC=CR (R==Ph, n-Pr, n-Hexyl) resulted in the formation of ketones AdCH2COR. 

Catalytic reactions were performed in CH2C12 under an 02 atmosphere Zn was used as an electron source and acetic acid as a proton donor (14). Under these reaction conditions ([2] [substrate] = 1 125), the production of adamantan-l-ol (248%), adamantan-2-ol (50%), and adamantan-2-one (108%) was observed. With cyclohexene as substrate, a mixture of cyclohexanol (54%), cyclohexanone (73%), and cyclohexene oxide (20%) was generated. In a similar experiment with cyclohexane, cyclohexanol (99%), and cyclohexanone (84%) were obtained. The product distribution is inconsistent with a free radical process for ada-mantane, the 3°/2° carbon reactivity ratio is 2.2. Control experiments demonstrated that both Zn dust and acetic acid were necessary, whereas larger quantities of acetic acid quenched the reaction (Table II). This may be due to the acidolysis of the n-oxo bond. Simple monomeric complexes such as FeClTPP (TPP is tetraphenylporphin), Fe(acac)3 (acac is acetylacetonate), and [Fe(HBpz3)2]+, 3, were inactive as catalysts under identical conditions. Furthermore, [Fe3+(Salen)]20, 1, did not show any reactivity. 

Adamantane-l-methoxycarbonyl (0.055 mmol) was dissolved in 150 ml THF, then treated with 1M LiAlH4 (69 mmol), and stirred 90 minutes at ambient temperature. The mixture was cooled to 0°C, then quenched sequentially with 5.1 ml water, 5.1 ml 15% NaOH, and 10.2 ml water. The mixture was stirred 15 minutes at ambient temperature and then filtered. The solids were washed twice with 100 ml EtOAc and then combined with the filtrate and concentrated. The residue was purified by flash column chromatography with silica gel using 10% EtOAc/CH2Cl2, and the product isolated in 96% yield as a white solid. 

Preparation of (S-(—)adamantane-l-phenylglycine hydrogen chloride salt... 

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