With sodium-liquid ammonia

Lauryl alcohol has been prepared by the reduction of the aldehyde with zinc dust and acetic acid 1 by the reduction of esters of lauric acid with sodium and absolute alcohol 2 or with sodium, liquid ammonia, and absolute alcohol 3 by the reduction of lauramide with sodium and amyl alcohol.4 The method in the above procedure is essentially that described by Levene and Allen.5... 

Two related alkaloids, grisabine (53 R = Me) and grisabutine (53 R = H), have been isolated from Abuta grisebachii Triana et Planchon. Their structures were determined by splitting the diphenyl ether linkage with sodium-liquid ammonia ... 

This type of reduction would be expected to proceed more readily with sodium, liquid ammonia, and alcohol, but so far only codeine has been recovered from this reaction [282], Under the same conditions, however, codeine methiodide is reduced to a phenolic base, m.p. 156° C., the analytical data for which are consistent with structures [xviii] and [xix]. This reaction is being investigated further [282]. 

Reduction of the C11 alkyne with sodium/liquid ammonia afforded the non-natural E-isomer. 

A second route to the 6H-pyrido[4,3-ft]carbazole nucleus of ellipticine involves as a key step the internal condensation of a 2-alkylskatolyl-piperidone. Le Goffic et al. (259) developed this synthesis in the 5,11-bisdemethyl series. When enamine 630 was condensed with 2-methyl-gramine (635), hydrolysis afforded the skatolylpiperidone (636). Cycliza-tion was carried out with glacial acetic acid under reflux, debenzylation with sodium/liquid ammonia, and dehydrogenation with palladium-charcoal to give 637. 

D-( — )-Armepavine and l-( -t )-armepavine have been obtained by reductive cleavage with sodium-liquid ammonia of a number of bis-benzylisoquinoline alkaloids (11, 12). A similar treatment of the pro-aporphine alkaloid pronuciferine has produced d-( — )-armepavine, a method which permits the correlation of its configuration with the aporphine alkaloids (79). 

Similar results were achieved when benzene was reduced with alkali metals in anhydrous methylamine at temperatures of 26-100°. Best yields of cyclohexene (up to 77.4%) were obtained with lithium at 85° [396]. Ethylamine [397] and especially ethylenediamine are even better solvents [398]. Benzene was reduced to cyclohexene and a small amount of cyclohexane [397, 398] ethylbenzene treated with lithium in ethylamine at —78° gave 75% of 1-ethyl-cyclohexene whereas at 17° a mixture of 45% of 1-ethylcyclohexene and 55% of ethylcyclohexane was obtained [397], Xylenes m- and p-) yielded non-conjugated 2,5-dihydro derivatives, l,3-dimethyl-3,6-cyclohexadiene and 1,4-dimethyl-1,4-cyclohexadiene, respectively, on reduction with sodium in liquid ammonia in the presence of ethanol (in poor yields) [399]. Reduction of diphenyl with sodium or calcium in liquid ammonia at —70° afforded mainly 1-phenylcyclohexene [400] whereas with sodium in ammonia at 120-125° mainly phenylcyclohexane [393] was formed. 

The ENDOR technique refers to electron-nuclear double resonance. This consists of the effect on a partially saturated ESR line of simultaneously irradiating the sample with a radiofrequency to induce nuclear resonance transitions of hyperfine coupled nuclei. It may enable one to obtain information about signs of coupling constants. ELDOR is the technique corresponding to electron-electron double resonance. Such techniques, coupled with TRIPLE resonance, have been utilized and well described in a discussion of pyridine and 4,4-bipyridyl radical anion ESR spectra measured in sodium/liquid ammonia (80JMR<41)17). 

Pyrroles are not reduced by sodium in liquid ammonia, but the Birch reduction of 2-furoic acid with lithium in liquid ammonia gives the 2,5-dihydro derivative in 90% yield (780PP94). Sodium-liquid ammonia-methanol reduction of thiophene gives a mixture of A2- and A3- dihydrothiophenes together with butenethiols. Reductive metallation of 1,3-diphenylisobenzofuran results in stereoselective formation of the cis- 1,3-dihydro derivative (Scheme 36) (80JOC3982). 

Application of this reaction to 2, 2-anhydrouridine (LXXXVII) led to a 3-substituted nucleoside (CIV) which, upon acylation followed by reduction with Raney nickel, yielded 3-deoxyuridine (CV, R = uracilyl). Reductive cleavage of CV, by the sodium-liquid ammonia procedure,72 afforded 3-deoxy-D-en/fAro-pentose ( 3-deoxy-D-ribose ), a result which establishes position 3 as the site originally containing the ethylthio function. The authors suggest,248 as a plausible route to CIV, the initial formation of the anion CII, followed by formation of the 2,3-anhydride structure. The anhydride (CIII) is then attacked, at C3, by the ethanethiol ion, to yield... 

Tetraphenylphosphonium Tris[benzcnetellurolato]mercurate(II)7 0.68 g (3.0 mmol) of sodium benzenetellurolate and 2.16 g (3,3 mmol) of mercury bis[benzenetellurolatc] are dissolved in 30 ml of liquid ammonia, and this solution is poured into 70 ml of liquid ammonia containing 2.25 g (6 mmol) of tetraphenylphosphonium chloride. The resultant mixture is filtered, the solid is washed five times with boiling liquid ammonia, and then dissolved in a small amount of tetrahydrofuran. Ethanol is added to this solution to precipitate the amber-colored solid which is stable in dry air but decomposes in sunlight yield 2.8 g (80%) m.p. 130° (dec.). 

Alkaline medium, however, is not always suitable since branched-chain alkyl halides are subject to elimination, and there are striking changes in orientation of substitution with unsymmetrically substituted imidazoles. Only low yields of l-(l-imidazolyl)-2-methyl-propane are obtained in the reaction of imidazole with l-iodo-2-methylpropane in sodium-liquid ammonia. 

Use of cyclopentene, frans-hex-3-ene and frans-oct-4-ene afforded the ene adducts in good yield with a diastereomeric excess of 86 14 in each case. The diastereoselectivity observed using di-(—)-( / ,25)-2-phenyl-l-cyclohexyl diazenedicarboxylate as a chiral azo-enophile offered a significant improvement over the use of di-(-)-menthyl azodicarboxylate where the level of asymmetric induction achieved in Lewis acid-mediated ene reactions with simple alkenes was not impressive. Moreover, it proved difficult to cleave the N-N bond in the menthyl ester azo-ene adducts whereas sodium/liquid ammonia was used to smoothly cleave the N-N bond in the diacylhydrazine adducts formed using di-(—)-(l/ ,25)-2-phenyl-l-cyclohexyl diazenedicarboxylate as azo-enophile. 

Mercaptopyrazine in aqueous hydrochloric or acetic acids was chlorinated to give the sulfonyl chloride which with excess liquid ammonia gave 2-sulfamoyl-pyrazine (1006, 1153). Direct sulfonation of the pyrazine ring has never been reported (819) but 2-sulfopyrazine (17) has been prepared from 2-chloropyrazine and aqueous sodium sulfite at 150° (819), and from 2-fluoropyrazine and aqueous sodium sulfite at reflux for 2 hours (882, 884). 2-Amino-3-mercaptopyrazine in aqueous sodium hydroxide with concentrated ammonia and sodium hypochlorite has been shown to give 2-amino-3-sulfamoylpyrazine (1101). 

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