By Wolff-Kishner reduction

The latter compound can be isolated from the reaction mixture by chromatography on acid-washed alumina. Similar treatment of the trans-ketone (117a) followed by isolation and chromatography on alumina gives the same equilibrium mixture. The structure of the thermodynamically more stable ketone (116a) was proved by its conversion by Wolff-Kishner reduction to the hydrocarbon (118) independently synthesized from the known... 

Docosanedioic acid has been prepared by Wolff-Kishner reduction of 6,17-diketodocosanedioic acid, formed by reaction of the half-ester acid chloride of adipic acid with the a,co-cadmium derivative of decane (%26 overall yield).3 Reduction of Wolff-Kishner method, followed by simultaneous reduction and desulfurization with Raney nickel of the 2,5-bis(co-carboxyoctyl)thiophene pro-... 

Cholest-3-ene has been prepared previously by deamination of 5/3-cholestan-3 -yl amine,by reduction of a mixture of 4 -bromo-5 -cholestan-3a-ol and its epimer with zinc in acetic acid, and as component of a mixture of cholestenes by Wolff-Kishner reduction of cholest-4-en-3-one. ... 

Ganter has developed three different approaches to tricyclo[5.2.1.0 ]decane (403), yet another of the nineteen isomeric hydrocarbons of adamantaneland As seen in Scheme XXXIII, the routes involve intramolecular cyclization of keto tosylate 399 followed by Wolff-Kishner reduction of the resulting ketone, thermo-cyclization of 400 and subsequent dechlorination, hydrogenation, and photocycli-zation of aldehydes 401. Majerski s approach involved hypoiodite cleavage of alcohol 402... 

Tetrahydrobenzo[6]thiophene may be prepared by Clem-mensen355 or Huang-Minlon194,356,436 reduction of 4,5,6,7-tetra-hydrobenzo[6]thiophen-4-one (103) or by Wolff-Kishner reduction of... 

Indolizines with a saturated six-membered ring may be obtained from pyrrole or furan derivatives.225,226 The reaction of 3,4-dimethylpyrryl-magnesium bromide with y-chlorobutyronitrile followed by dilute acid gave 5,6,7,8-tetrahydro-l,2-dimethyl-5-oxoindolizine. 5,6,7,8-Tetrahy-droindolizine can be obtained by the cyclodehydration of 3-(2-furyl)-propylamine over alumina at 400°C. The same product is obtained by the treatment of 3-(2-pyrryl)propyl cyanide with hydrogen chloride in the presence of boron trifluoride etherate catalyst, followed by Wolff-Kishner reduction of the intermediate ketone. 

Gymnamine (C19H2603N2 amorphous picrate, mp 260°) has structure 101 as determined by spectral methods. Hydrolysis followed by Wolff-Kishner reduction converted it into lycodine (102) (77). 

A modified Houben-Hoesch reaction of the nitrile 84 gave 31% of the azaazulenone 85, which was transformed to 63 by Wolff-Kishner reduction (62JOC1652). Similarly, 86 has been converted into 87 (78CB2407). Acid 88 gave ketone 89 with polyphosphoric acid (69JCS(C)1028) as was 91 formed from 90 (79JHC1443). 

The UV- and IR-spectra indicate the presence of an a-oxindole chromo-phore superimposable without conjugation upon the Me02C=C0R chromophore characteristic of those of corynantheine and of ajmalicine. Hydrolysis followed by Wolff-Kishner reduction of dihydrocorynoxeine and of corynoxine yields two bases, dihydrocorynoxeinine (CXIX) and corynoxinine (CXX), respectively, which possess only the oxindole chromophore. The former base, dihydrocorynoxeine, has been shown to be identical with rhynchophylline (CXVIIb) (77), which possesses the ethyl side chain and hence corynoxeine (CXVIIa) has the vinyl chain (76). 

The carbonyl-bridged pyrrolo-diazocine 196 was converted, in good yield, into the corresponding methylene-bridged system 197 by Wolff-Kishner reduction (Scheme 34) <1999J(P1)3623>. 

The acetyl derivative (30) may be converted by Wolff-Kishner reduction into l,4-dimethyl-3-ethyl-3-piperideine (31).26 The latter compound is obtained in 17% yield also by dehydration of 1,4-dimethyl-3-( l-hydroxyethyl)piperidine (32) by the xanthate method.28 On the other hand, dehydration of the carbinol (32) with phosphorus pentoxide in toluene or by heating in concentrated hydrochloric aoid gives a mixture of isomeric l,4-dimethyl-3-ethylidenepiperidines (33a, b).28... 

Dihydromorphine has also been converted to 64 (R = R = H) and the 6-oxo group removed by Wolff-Kishner reduction/72 Bromination (1 mol Br2/HOAc) of (-)-4-hydroxy-N-methylmorphinan-6-one has been shown by 13C nmr to occur predominantly in the 1 position/79 ... 

Tritylone alcohol reacts readily with alcohols to give tritylone ethers. Selective reaction of primary alcohols in the presence of secondary alcohols is possible. These new ethers are more stable to acid than trityl ethers. They can be cleaved by Wolff Kishner reduction. ... 

When mesembrenine was catalytically hydrogenated over palladium on charcoal ( + )-mesembrine was isolated from which ( + )-mesembrane could be produced by Wolff-Kishner reduction (8) consequently only structure XXVIII is possible for mesembrenine. 

Many acylcyclopropanes have been converted to the corresponding alkylcyclopropanes by Wolff-Kishner reduction, in most cases under the Huang-Minlon conditions. 

Similar observations of C-NMR chemical shifts were obtained for a pair of geometrical isomers, 19 and 20 170), to establish the same regularity. Isomer 19 was prepared from 2 by Wolff-Kishner reduction, and 20 was obtained from 3 via the corresponding aldehyde (Scheme 5). 

Cyclopropanes by Wolff-Kishner Reduction of a,/MJnsaturated Ketones... 

The method has now been used to synthesize 9,10-dimethyl-trarcs-l-decalones,11 which have the characteristic C/D ring system of pentacyclic triterpenes. Thus i ruction of the hydroxy enol ether (9) with the Simmons-Smith reagent gives the cyclopropyl ether (10). Cleavage with 7% methanolic hydrochloric acid leads to the hydroxy ketone (11), convertible by Wolff-Kishner reduction followed by oxidation into (12). 

C2 symmetry), a high-symmetry chiral cage-shaped tricyclic hydrocarbon closely related to D2 twistane. Wagner-Meerwein rearrangement (144) of the unsaturated carboxylic acid (-)-151 provided the lactone (-)-168, which in turn was converted into the ketone (+)-170 via a series of intermediates, including the mesylate 169 whose intramolecular alkylation was a crucial step in this approach. Removal of the carbonyl group by Wolff-Kishner reduction completed the synthesis of (+)-brexane (171) (145). 

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