Wolf-Kishner reduction

Hydrogenation and Wolf-Kishner reduction in either order, e,g. ... 

Wittig reaction -selective 108 Wolf-Kishner reduction (see ketone to methylene)... 

Alkylfurans may be prepared by decarboxylation of alkylfurancarboxylic acids or by Wolf-Kishner reduction of furan aldehydes and ketones. The direct alkylation of furan is also useful in obtaining alkylfurans. 

The deuterium labelling has been achieved also by Wolf-Kishner reduction of 2-(3-xenyl)cyclohexanone. The hydrazone of 56 dissolved in diethylene glycol containing D2O was heated first at 120 °C for 15 min and, after addition of KOH, heated at 230 °C for an additional two hours. The product 59 has been identified by the mass spectrum as the predominant constituent. 

The Clemmensen reduction was accompanied by D/H exchange via acid-catalysed enolization of the carbonyl group, resulting in the production of deuteriated compounds 57 and 58 with various numbers of deuterium atoms. The mixture of the compound 59 obtained by the Wolf-Kishner reduction was predominantly labelled at position 2. This has been proved by the 13C-NMR spectrum. Isotope shift and loss intensivity on substituted C(2) carbon signals have been observed54,55. 

A slightly more vigorous method, known as the Wolf-Kishner reduction, is driven by the elimination of nitrogen gas from a hydrazone. Hot concentrated sodium hydroxide solution deprotonates the hydrazone, which can then eliminate an alkyl anion—a reaction you would usually be wary of writing, but which is made possible by the thermodynamic stability of N2. 

In a similar way [lxxxii, R = H] was reduced to [xcvxn], which converted by Wolf-Kishner reduction to [xoix],. which in turn was reduced with lithium aluminium hydride and methylated to give dZ-/3-dihydrodesoxycodoine-B methyl ether [c]. The product was compared, by means of the infra-red absorption spectra, with dihydro-desoxycodeine-B methyl ether prepared from dihydrothebainol-B [oi] and with /3-dihydrodesoxycodeine-B methyl ether prepared from /3-dihydrothobainol-B, which is the C-14 epimor of [oi]. The spootra of... 

Acyl products that are formed can be reduced by reactions such as Clemmenson or Wolf-Kishner reductions. 

The carbonyl groups of aldehydes and ketones can be converted to methylene groups by Clemmenson and Wolf-Kishner reduction reactions. 

McNulty and Capretta disclosed the synthesis and use of phosphorinane ligands [115], and demonstrated catalytic activity in the amination of deactivated aryl chlorides. However, the use of NaOt-Bu as a strong base at elevated temperatures limits the scope of these compounds. The ligand scaffold is readily accessed by double conjugate additions of monosubstituted phosphines to phorone, followed by Wolf-Kishner reduction of the remaining ketone. 

Wolf-Kishner reduction. The yield of the acylation step seemed to depend on the stability of the ring size of the product, providing the cyclohexano compound in highest yield. 

---