Decalin carboxylic acid

A setup similar to the preceding one is used in this experiment except that provision should be made for heating the reaction vessel (steam bath, oil bath, or mantle). Lithium aluminum hydride (10 g, 0.26 mole) is dissolved in 200 ml of dry -butyl ether and heated with stirring to 100°. A solution of 9.1 g (0.05 mole) of ra j-9-decalin-carboxylic acid (Chapter 16, Section I) in 100 ml of dry -butyl ether is added dropwise over about 30 minutes. The stirring and heating are continued for 4 days, after which the mixture is cooled and water is slowly added to decompose excess hydride. Dilute hydrochloric acid is added to dissolve the salts, and the ether layer is separated, washed with bicarbonate solution then water, and dried. The solvent is removed by distillation, and the residue is recrystallized from aqueous ethanol, mp 77-78°, yield 80-95 %. 

Highly unsaturated cyclic compounds likewise do not react to give di-or tricarboxylic acids, but tertiary monocarboxylic acids are obtained with CO/HgO by a transannular reaction with hydride transfer and formation of bi- or tricyclic systems at the bridgehead. Thus, cyclodecadiene-1,5 reacts to give a mixture of cis- and trans decalin carboxylic acid [624] and cyclododecatriene-1,5,9 reacts to give a mixture of isomeric tertiary per-hydroacenaphthene carboxylic acids. 

Decalin unit 121, an intermediate in the total synthesis of compactin, has been prepared by intramolecular cycloaddition reaction [117] of trienone-carboxylic acid 122 carried out under either thermal conditions or microwave irradiation. The desired cxo-adduct 123 was the major stereoisomer (Equation 2.34). Similar results were observed in the cycloadditions of the corresponding esters. 

Then, the examples from Reference 23, that focus on retention of the selected binary mixtures of the test analytes (one comprising carboxylic acid and ketone and the other made of alcohol and ketone), chromatographed under the deliberately mild working conditions (microcrystalline cellulose was used as adsorbent and either decalin or n-octane as the monocomponent mobile phase) will be discussed. One of the test solutes in each binary mixture (either acid or alcohol) can be viewed as... 

The photolysis of cis- and tai/is-decalin-9-carboxylic acid imidazolide has also been investigated. ... 

After having developed a reliable route to the enantiopure carboxylic acid 4a, we next turned our attention to gain access to the enantiopure decalin fragment. One of the most efficient approaches to this structural motif is the intramolecular Diels-Alder reaction. The first systematic studies in the racemic series were performed by Roush and co-workers in 1981 (Roush and Hall 1981). Evans (Evans et al. 1984, 1988) and Oppolzer (Oppolzer and Dupuis 1985) showed that chiral auxiliaries in combination with strong Lewis acids allowed the generation of the endo adducts with excellent diastereoselectivities (Scheme 5). Recently, chiral Lewis acid catalysts were successfully used by Evans (Evans et al. 1999) and Corey (Zhou et al. 2003). 

It has been shown that perfluorinated j3-diketonates are excellent catalysts for oxidation reactions in perfluorinated solvents [26]. The nickel catalyst Ni(39)2, prepared by reaction of the -diketone 39 [27] with NiCl2, catalyzes the oxidation of various (functionalized) aromatic and aliphatic aldehydes to the corresponding carboxylic acids in 76 to 87% yield in a solvent system of perfluoro-decaline and toluene at 64 °C under 02-atmosphere Eq. (16). 

The nucleophilic olefin is electron deficient, e.g., treating the protected ( )-2,3,6,7-un-saturated carboxylic acid 1 with acetic acid and sulphuric acid protonates the tetrasubstituted olefin in the first step generating a tertiary carbocation 2. Attack of the electron-deficient nucleophilic double bond is slow enough to allow the initial cation to undergo configurational relaxation. Termination of cyclization then takes place via a concerted alkylation, proton-elimination step and the trans-decalin 3 is formed stereoselectively21. 

The first studies in liquid phase have been carried out by Azinger co., on ozonation of octadecane [16], On the basis of the composition of the carboxylic acids and their yield they predict that ozone attacks directly the CH groups. Upon ozonolysis of decalin and adamantine containing the tert-CH-bonds the formation of tert- alcohols is observed. In cyclohexane ozone reacts with the CH -groups and giving and increasing amounts of cyclohexanol and cyclohexanone [16]. 

The occurrence of carbocationic intermediates in the Hofer-Moest variant of the Kolbe reaction can lead to numerous rearrangement processes. For example, electrolysis of carboxylic acid 68 in methanol results in the oxidative ring opening of the norbomane skeleton[30]. In a similar manner, GroB-type fragmentation of the decaline derivative 70 affords the 10-membered-ring ketone 71 in good yield (Scheme 12) [31]. 

Dehydrogenation of the lactone acid (XVII) with palladium-charcoal yielded 2-ethylnaphthalene and under the same conditions the acid X afforded 2-ethyl-3-methylnaphthalene. The formation of these two hydrocarbons disproved the earlier hypotheses that the carbonyl group of himbacine was attached to a tertiary carbon atom and that the ethyl groups of 2-ethyl-6-methylpyridine and 2-ethyl-3-methylnaphthalene, isolated from the selenium dehydrogenation of himbacine, were derived from the same structure in the alkaloid. Moreover, since the results of the Hofmann degradation and the oxidation experiments had shown that the 6-(l,2-dimethylpiperidyl)-vinyl group was attached to a decalin residue by reason of the formation of the C-13 ketones, it only remained to establish the point of attachment. For this purpose the carboxyl group... 

Since lactonization of 149 (R = H) with a deuterium located at position 2 occurred without loss of the label, a mechanism involving simple epimerization of the carboxyl group is excluded. Further the facile lactonization of unsaturated spiro acid 152 to the isomeric decalin y-lactones tends to support a mechanism for the lactonization of 149 (R = H) via a spiro intermediate. 

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