1-Adamantanols

Another feature of systems that are subject to B-strain is their reluctance to form strained substitution products. The cationic intermediates usually escape to elimination products in preference to capture by a nucleophile. Rearrangements are also common. 2-Methyl-2-adamantyl p-nitrobenzoate gives 82% methyleneadamantane by elimination and 18% 2-methyl-2-adamantanol by substitution in aqueous acetone. Elimination accounts for 95% of the product from 2-neopentyl-2-adaman l p-nitrobenzoate. The major product (83%) from 2-r-butyl-2-adamantyl p-nitrobenzoate is the rearranged alkene 5. 

Tnfluoroacetic anhydnde in a mixture with sulfuric acid is an efficient reagent for the sulfonylation of aromatic compounds [44] The reaction of benzene with this system in nitromethane at room temperature gives diphenyl sulfone in 61% yield Alkyl and alkoxy benzenes under similar conditions form the corresponding diaryl sulfones in almost quantitative yield, whereas yields of sulfones from deactivated arenes such as chlorobenzene are substantially lower [44] The same reagent (tnfluoroacetic anhydride-sulfunc acid) reacts with adamantane and its derivatives with formation of isomeric adamantanols, adamantanones, and cyclic sultones [45]... 

A 500-ml flask is equipped with a condenser and a magnetic stirrer and charged with 175 ml of water, 18 ml ofTHF, lOg of potassium carbonate, 6.5 g of silver nitrate, and 10 g of 1-bromoadamantane. The mixture is heated in a boiling water bath for 1 hour with stirring, cooled, and the crystallized 1-adamantanol is collected by filtration. It may be purified by dissolving it in THF and diluting the solution with water. The product has mp 289-290°. 

Adsorption of various organic compounds (e.g., cyclohexanol, adamantanol-1, and camphor) has been studied at a renewed Sn + Pb alloy/electrolyte interface.820-824 The time variation of the surface composition depends on the solution composition, the nature and concentration of the surface-active substance, and on E. The " of cyclohexanol for just-renewed Sn + Pb alloys shifts toward more negative E with time, i.e., as the amount of Pb at the Sn + Pb alloy surface increases. 

Solvent-grade benzene was dried over sodium wire prior to use. If the benzene is wet, a considerable amount of starting 1-adamantanol remains unreacted owing to hydrolysis of lead tetraacetate. 

The conditions for gas chromatography are given in Note 9. The product was found mainly in fractions 2-20 by the submitters. The first 25-ml. fraction contained considerable amounts of byproducts, while fractions 21 and higher contained 1-adamantanol. The checkers collected 10-ml. fractions with an automatic fraction collector. 

Protoadamantanone has been prepared by the nitrous acid deamination of 2-amino-l-adamantanol (77%), by aprotic diazo-tization of endo-7-aminomethylbicyclo[3.3.1]nonan-3-one in benzene with an equivalent amount of acetic acid (67%), and by thermolysis of 1-adamantyl hypohalites followed by base-promoted cyclization of the resulting halo ketones (32-37%)." In spite of low and erratic yields, the last reaction sequence has provided the most convenient route to the protoadamantanes, since the other two approaches require lengthy syntheses of the starting materials. 

TERTIARY ALCOHOLS FROM HYDROCARBONS BY OZONATION ON SILICA GEL 1-ADAMANTANOL... 

A gas chromatographic analysis by the checkers (see Note 10) on the material in the third crop from one run showed a major peak for 1-adamanttUiol and a second minor peak having an area ca. 12% of that of the major peak. In another run the area of the peak from this by-product in the third crop was less than 2% relative to that of 1-adamantanol. 

A yield of 5.8 g. (877o), m.p. 280-282°, was obtained by the submitters. The infrared spectrum, proton and carbon-13 magnetic resonance spectra, and mass spectrum of the product were identical to those of an authentic sample of 1-adamantanol. A mixed melting point with an authentic sample of 1-adamantanol showed no depression. 

This dry ozonation procedure is a general method for hydrox-ylation of tertiary carbon atoms in saturated compounds (Table 1). The substitution reaction occurs with predominant retention of configuration. Thus cis-decalin gives the cis-l-decalol, whereas cis- and frans-l,4-dimethylcyclohexane afford cis- and trans-1,4-dimethylcyclohexanol, respectively. The amount of epimeric alcohol formed in these ozonation reactions is usually less than 1%. The tertiary alcohols may be further oxidized to diols by repeating the ozonation however, the yields in these reactions are poorer. For instance, 1-adamantanol is oxidized to 1,3-adamantane-diol in 43% yield. Secondary alcohols are converted to the corresponding ketone. This method has been employed for the hydroxylation of tertiary positions in saturated acetates and bromides. 

Adamantanol has been prepared by oxidation of adamantane with peroxyacetic acetic" and by hydrolysis of 1-bromoadamantane with silver nitrate s or hydrochloric acid. ... 

A. endo-7-Iodomethylbicyclo[3.3.1]nonan-3-one. A 2-1., threenecked, round-bottomed flask equipped with an eflicient mechanical stirrer and a reflux condenser is charged with 600 ml. of dry ben2 ene (Note 1). The flask is immersed in a water bath, stirring is initiated, and 58.3 g. (0.132 mole) of lead tetraacetate (Note 2), 37.4 g. (0.147 mole) of iodine, and 10.0 g. (0.066 mole) of 1-adamantanol (Note 3) are added (Note 4). The bath temperature is gradually raised to 80° over a 20-minute period and is then allowed to cool to 70-75°. Stirring is continued for 2 hours at 70-75° (Note 5) and for an additional hour while the mixtiu e is cooled to room temperature. The inorganic salts are filtered and carefully washed with five 50-ml. portions of ethyl ether. The... 

Adamantanol is available from the following three suppliers Aldrich Chemical Company, Inc., Fluka AG, Buchs, Switzerland E. Merck, Darmstadt, Germany. It may also be prepared from adamantane by bromination to 1-bromoadamantane and hydrolysis. Adamantane is sold by the same three suppliers. 

The temperature of the bath should be carefully maintained in this range. At temperatures below 70° the reaction is much slower and increased amounts of unreacted 1-adamantanol will contaminate the product. At temperatures above 75° the amount of tar in the product is increased. 

The procedure described here is a modification of one involving the thermal fragmentation of 1-adamantyl hypoiodite and cycliza-tion of the resulting iodo ketone/ By means of this procedure, 4-protoadamantanone is obtained from 1-adamantanol with consistent yields in the range of 71 to 82% and a purity greater than 98%. This method is also applicable to the preparation of other polycyclic ketones from the related bridgehead alcohols with a-bridges of zero, one, or two carbon atoms (see Table I). 

Carbonylation-oxidation of the THF complexes (S)-58 and (R)-58 afforded the optically active (3 )-(+)-2-methyl-l-adamantanol (3)-60 and (R)-(—)-2-methyl-l-adamantanol (R)-60, respectively (Scheme 24) <2003MC121, B-2003MI97>. 

Secondary Alkyl Alcohols. Treatment of secondary alkyl alcohols with tri-fluoroacetic acid and organosilicon hydrides results only in the formation of the trifluoroacetate esters no reduction is reported to occur.1,2 Reduction of secondary alkyl alcohols does take place when very strong Lewis acids such as boron trifluoride126 129 or aluminum chloride136,146 are used. For example, treatment of a dichlo-romethane solution of 2-adamantanol and triethy lsilane (1.3 equivalents) with boron trifluoride gas at room temperature for 15 minutes gives upon workup a 98% yield of the hydrocarbon adamantane along with fluorotriethylsilane (Eq. 10).129... 

Similarly, and in contrast to the behavior of its secondary isomer, 2-adaman-tanol, 1-adamantanol undergoes smooth, quantitative reduction to adamantane in less than an hour at room temperature in dichloromethane solution containing triethylsilane under the catalysis of either free boron trifluoride129 or boron trifluoride etherate (Eq. 13).143... 

Trimethylsilane in pentane is a particularly good system for the TMSI-catalyzed reductive coupling of tertiary alkoxytrimethylsilanes with aldehydes to form sterically crowded tertiary-primary ethers.337 In this way, 1 -(tert-butoxymethyl)-3-methylbenzene is formed in 87% yield (Eq. 184).338 Reaction of terephthaldehyde with two equivalents of the trimethylsilyl ether of 1-adamantanol under these conditions leads to a good yield of the diadamantyl ether of 1,4-benzenedimethanol (Eq. 185).338... 

Boyle, T. J. Pearson, A. T. Schwartz, R. W. 1994. Synthesis and characterization of Group IV metal adamantanol alkoxides as potential PZT precursors. Ceram. Trans. 43 79-87. 

Synthesis of 1-Adamantanol from Adamantane through Regioselective Hydroxyiation by Streptomyces griseoplanus Cells... 

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