4-Adamantanone

Submitted by H. W. Geluk and V. G. Keizer1 Checked by L. Foley, W. Jackson, and A. Brossi 

A 750-ml. portion of this suspension of crude adamantanone is transferred to a 2-1. round-bottomed flask, equipped for steam distillation (Notes 7 and 8), which is placed in a heating mantle. The contents of the distillation flask are heated to 70° then the external heating is turned off (Note 9) and steam is introduced carefully through both inlet tubes (Note 10). The two layers of distillate are separated, and the aqueous layer is extracted with two 75-ml. portions of methylene chloride. This steam distillation procedure is then repeated with the second half of the suspension of crude adamantanone. The organic extracts are combined, washed with 100 ml. of aqueous, saturated sodium chloride, and dried over anhydrous sodium sulfate, and the solvent is evaporated under reduced pressure. The yield of adamantanone is 52-53 g. (47-48%) (Notes 11, 12, and 13). 

The stirrer should be placed just under the surface of the sulfuric acid. The flask should be filled to at least three-quarters of its volume so the sublimed material can be rinsed from the walls by vigorous stirring. 

Sulfur dioxide generated during the reaction can escape 

The required amount of 98% sulfuric acid is prepared by adding 53 ml. of fuming sulfuric acid (65% free sulfur trioxide) to 530 ml. of 96% sulfuric acid or by adding 120 ml. of fuming sulfuric acid (30-33% free sulfur trioxide) to 480 ml. of 96% sulfuric acid. 

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Many [2 + 2] photocycloadditions have not been assigned a definitive mechanism, but they serve well as synthetic methods. Thiones add vinyl ethers to give thietanes in very good yields (Section 5.14.4.1.2), and interesting wavelength-stereochemistry relations were found in the photoaddition of 2-adamantanone to dicyanoethylene (Section 5.14.4.1.2). Diheterocyclobutanes can also be prepared by [2 + 2] photocycloadditions (Section 5.13.3.3). 

Commercial 2-adamantanone (Aldrich Chemical Company, Inc.) was used. 

Scheme 123 Experimental conditions (i) Ag02CPh, THF (b) 2-adamantanone (iv) C3H5MgCl, THF. ...

Strain can exert other influences on molecules. l-Aza-2-adamantanone (100) is... 

Free intermediate thioaldehydes 598 or 602 and the selenoaldehydes 605 and HMDSO 7 are obtained in THF at 0°C on treatment of aliphatic and aromatic aldehydes with bis(trimethylsilyl)thiane 601 or bis(trimethylsilyl)selenide 604 in the presence of traces of butyllithium, while trapping the sensitive intermediate thio- or selenoaldehydes 602 and 605 with cyclopentadiene or cyclohexadiene to furnish mixtures of endo and exo Diels-Alder adducts such as 603 a and 606 a and 603 b and 603 b [148-150], the exo/endo ratio of which can be controlled [150] (Scheme 5.48). Analogous reaction of ketones such as 2-adamantanone or acetylene ketones with MesSiXSiMes 608 (a. X=S (601) b. X=Se (604)) in the presence of... 

In the present study isomorphic substitution of Al with Sn [11-13] in the silicalite framework was attempted in order to induce catalytic functionalities and these catalysts was studied for Baeyer-Villiger oxidation of 2-adamantanone and norboranone. 

Table 1 Selected structural and spectroscopic properties of /V-acyloxy-iV-alkox yam ides 31b and 31f, -urea 38i, -carbamate 39g, theoretical models 40 and 41 and 1-aza-2-adamantanone 1...

Crystal data for all four amides are uniformly similar. While amides 31b and 31f (IXnI = 65.6° and 65.3°, respectively) are more pyramidal than the urea and carbamate (IxnI = 57.1° and 56.3°, respectively) all four possess sp3-hybridised nitrogens. Average angles at nitrogen for the two amides are smaller than that required by pure tetrahedral geometry as exemplified by the tetrahedral nitrogen in l-aza-2-adamantanone 1. 

The amide carbonyl vibrational frequencies of A-acyloxy-Af-alkoxyamides are similar to that observed for the twisted l-aza-2-adamantanone (98, 1731 cm ) . It is apparent from the extensive data available for both A-chlorohydroxamic esters (Table 2, Section in.B.2) and Af-acyloxy-A-alkoxyamides that when an amide nitrogen lone pair loses conjugation with the carbonyl (either through twisting/pyramidalization or, in the case of anomeric amides, pyramidalization alone), the configuration is analogous to an ester rather than a ketone. As with esters, acid halides and anhydrides or diacyl peroxides , the carbonyl stretch frequency is higher than that of ketones and aldehydes... 

Attempted preparation of the other adamantane 1,3-diyl dications was also futile. Thus, ionization of 2-methyl-5-bromoadamantane in FS03H-SbF5/S02 gave only the monocation donor-acceptor complex (48). Even the ionization of the 5-bromo-2-adamantanone gave the carboxonium donor-acceptor complex (49)." ... 

Rgure i. High-Field Portion of the H-NMR Spectrum of (4R)-4-Bromo-2-adamantanone, Recorded at 80 MHz (top) and 400 MHz (bottom) taken with permission from ref 14. 

Georgiev et al. [82] have described the preparation of novel adamantine-spiro-heterocyclic (3-lactams 34, 35, and 40. Grignard reaction of 2-adamantanone 31 with benzylmagnesium halide provided the compound 32, which on further dehydration afforded corresponding analogs 33. Condensation reaction of compound 33 with chlorosulfonyl isocyanate in ether afforded spiro-(3-lactams 34 and cycloaddition with chlorosulfonyl isocyanate resulted in the formation of spiro product 35 (Scheme 10). 

The chirality of (15 )-2-adamantanone-4-13C (87) and (lS )-2,4-adamantanedione-4-13C (88) is solely due to 13C substitution. Since the 13C ring carbon of 87 is located in a positive octant, from the negative Cotton effect of 87, it follows that 13 C makes a smaller contribution than 12C. Diketone 88 exhibits three CD bonds with remarkably large amplitudes, which were attributed to different n - tt transitions195. 

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