Bisulfite addition to carbonyl

Hydrogen Sulfite (Bisulfite) Addition to Carbonyl Compounds... 

The rates of nucleophilic additions to adamantanone have been studied in an attempt to determine the structure of the transition states of nucleophilic additions to carbonyl compounds in general. The kinetic analysis suggests that the transition states of borohydride reductions of ketones are product-like while for bisulfite additions the transition states are reactant-like 367). A similar analysis 36 ) of data obtained for photo-initiated oxetane formation (trans-dicyanoethylene + carbonyl compound) 3681 indicates a reactant-like transition state. 

Bisulfite (two waters) addition to carbonyl, cyclic Preliminary examination ... 

The reversible addition of sodium bisulfite to carbonyl groups is used ia the purification of aldehydes. Sodium bisulfite also is employed ia polymer and synthetic fiber manufacture ia several ways. In free-radical polymerization of vinyl and diene monomers, sodium bisulfite or metabisulfite is frequentiy used as the reduciag component of a so-called redox initiator (see Initiators). Sodium bisulfite is also used as a color preventative and is added as such during the coagulation of crepe mbber. 

Sodium bisulfite adds to the carbonyl double bond to give a hydroxysulfonate (bisulfite addition compound). 

The last nucleophile of this chapter, sodium bisulfite, NaHSC, adds to aldehydes and some ketones to give what is usually known as a bisulfite addition compound. The reaction occurs by nucleophilic attack of a lone pair on the carbonyl group, just like the attack of cyanide. This leaves a positively charged sulfur atom but a simple proton transfer leads to the product. 

The reaction is often carried out by adding mineral acid to a mixture of the carbonyl compound and aqueous sodium cyanide. In a useful modification, cyanide is added to the bisulfite addition product (Sec. 19.13) of the carbonyl compound, the bisulfite ion serving as the necessary acid ... 

Addition involves nucleophilic attack by bisulfite ion on carbonyl carbon, followed by attachment of a hydrogen ion to carbonyl oxygen ... 

Bisulfite Addition Products and the Bucherer Reaction. The addition of sodium bisulfite to aldehydes and some ketones superficially appears to involve the addition of the elements Na and HS03 to the carbonyl group. Kinetic studies, however, indicate that the reaction is complicated and probably involves sulfite rather than bisulfite ion.10 One possible mechanism is the following ... 

The inhibition of nonenzymic browning in foods, by sulfite, depends in part, at least, on the capture of such reactive intermediates as (90) and (91) and their conversion to the carbonyl-bisulfite addition compounds of sulfonic acids (89). These carbonyl-bisulfite addition compounds are comparatively stable, sulfur dioxide being only slowly liberated by the steam distillation of the free acid. 

The rates of these reactions vary with a change in the carbonyl compounds in a way very similar to that of the bisulfite additions. It is likely that the rates of these reactions are governed by a preliminary addition of the base ... 

Sodium bisulfite adds to aldehydes (most of them) to form bisulfite addition products. This utility is in separating a carbonyl compound from non-carbonyl compounds, The reaction is illustrated as follows ... 

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