Nitro compounds, carbanions from aliphatic

Nitro Anions Remov of a proton from an aliphatic nitro compound gives a carbanion (R2C-NO2) that can be alkylated at oxygen or carbon. ... 

Many of the compounds that undergo ready base-catalysed keto i enol prototropic changes, e.g. / -keto esters, l,3-(/ -) diketones, aliphatic nitro compounds, etc., form relatively stable carbanions, e.g. (25), that can often be isolated. Thus it is possible to obtain carbanions from the keto forms of the /J-keto ester (23a) and nitromethane (24a) and, under suitable conditions, to protonate them so as to obtain the pure enol forms (23b) and (24i>), respectively. It thus seems extremely probable that their interconversion follows the intermolecular pathway (a). The more acidic the substrate, i.e. the more stable the carbanion to which it gives rise, the greater the chance that prototropic interconversion will involve the carbanion as an intermediate. 

Removal of a proton from an aliphatic nitro compound gives a carbanion... 

Reaction of carbanions with TNB may result in the formation of new carbon-carbon bonds. Examples of adducts formed are (63) from ketones [166], (64) from aliphatic nitro compounds [167], and (65) from malononitrile [168]. ThCTe are various possibilities for furtho- reaction of these adducts. These include the formation of diadducts or of uicia-bridged adducts, such as (66), from suitable ketones [169,170] or from amidines, or of the ionization of the exocyclic hydrogen in (65) to give a dianion. 

---