Ketones sulfite addition

From the data obtained, it is assumed that the active nucleophile is the dianionic sulfite ion. This reaction is typical of conjugate sulfite addition to a,3-unsaturated ketones. It should be inferred that other active nucleophilic agents may behave in a similar manner. 

The sulfite addition products of aldehydes and ketones of fairly low molecular weight are quite soluble in water. The progress of the reaction may be nevertheless followed by the generation of heat. Most ketones of high molecular weight do not react but the reaction is quite general for the... 

Addition of sodium dithionite to formaldehyde yields the sodium salt of hydroxymethanesulfinic acid [79-25-4] H0CH2S02Na, which retains the useful reducing character of the sodium dithionite although somewhat attenuated in reactivity. The most important organic chemistry of sodium dithionite involves its use in reducing dyes, eg, anthraquinone vat dyes, sulfur dyes, and indigo, to their soluble leuco forms (see Dyes, anthraquinone). Dithionite can reduce various chromophores that are not reduced by sulfite. Dithionite can be used for the reduction of aldehydes and ketones to alcohols (348). Quantitative studies have been made of the reduction potential of dithionite as a function of pH and the concentration of other salts (349,350). 

Another arylation reaction which uses arenediazonium salts as reagents and is catalyzed by copper should be discussed in this section on Meerwein reactions. It is the Beech reaction (Scheme 10-49) in which ketoximes such as formaldoxime (10.13, R=H), acetaldoxime (10.13, R=CH3), and other ketoximes with aliphatic residues R are arylated (Beech, 1954). The primary products are arylated oximes (10.14) yielding a-arylated aldehydes (10.15, R=H) or ketones (10.15, R=alkyl). Obviously the C=N group of these oximes reacts like a C = C group in classical Meerwein reactions. It is interesting that the addition of some sodium sulfite is necessary for the Beech reaction (0.1 to 0.2 equivalent of CuS04 and 0.03 equivalent of Na2S03). 

Sodium sulfite, acid (saturated) dissolve 600 g of NaHS03 in water and dilute to 1 liter for the preparation of addition compounds with aldehydes and ketones prepare a saturated solution of sodium carbonate in water and saturate with sulfur dioxide. 

Several carbonyl additions have characteristics similar to those of cyanohydrin formation. A typical example is the addition of sodium hydrogen sulfite, which proceeds readily with good conversion in aqueous solution with most aldehydes, methyl ketones, and unhindered cyclic ketones to form a carbon-sulfur bond. No catalyst is required because sulfite is an efficient nucleophilic agent. The addition step evidently involves the sulfite ion—not hydrogen sulfite ion ... 

The role of the hydrogen sulfite is participation in a reversible l, 4-addition to the unsaturated ketone to hold it in the ketone form that then is converted to the imine by NH3 (Section 16-4C) and hence to the arenamine ... 

Pipet a 10-mL sample into a 100-mL cassia flask fitted with a stopper, and add 50 mL of a freshly prepared 30 in 100 solution of sodium sulfite. Add 2 drops of phenolphthalein TS, and neutralize with 50% (by volume) acetic acid solution. Heat the mixture in a boiling water bath, and shake the flask repeatedly, neutralizing the mixture from time to time by the addition of a few drops of the 50% acetic acid solution, stoppering the flask to prevent loss of volatile material. After no coloration appears upon the addition of a few more drops of phenolphthalein TS and heating for 15 min, cool to room temperature. When the liquids have separated completely, add sufficient sodium sulfite solution to raise the lower level of the oily layer within the graduated portion of the neck of the flask. Calculate the percentage, by volume, of the aldehyde or ketone by the equation... 

The cyanohydrin of methyl pentadecafluoroheptyl ketone 49 is synthesized by a two-step process addition of sodium hydrogen sulfite and subsequent treatment with sodium cyanide. 

Sodium hydrogen sulfite also adds to aldehydes and some ketones to form hydroxysulfonic acids (22) (Scheme 20). The nucleophilic addition generally goes well with aldehydes and methyl ketones of the type RCOMe, where R is a primary alkyl group. Since the water soluble products are readily converted back to the carbonyl compounds by treatment with dilute acid, the reaction provides a useful method for purification of carbonyl compounds from non-carbonyl impurities. 

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 My values for n-glucosone and its dimethyl acetal have already been discussed (see p. 272). In contrast to the migrations of the aldoses studied and, in particular, to the strong tendency of the cyclic keto carbohydrates to form addition products with hydrogen sulfite, n-fructose and other hexuloses and pentuloses studied showed no migration. This is probably mainly due to steric hindrance analogous to the reluctance of aliphatic ketones to form addition products with hydrogen sulfite (as compared with the behavior of aldehydes or cyclic ketones). 

Addition to aromatic ketones An extensive study of the reaction of CSI with aromatic ketones (1) presents evidence that the first step is formation of a 3-keto carboxamide (2), which can react with another molecule of CSI to form a malonamide (3). Generally, however, (2) reacts with CSI to form, after reductive hydrolysis with sodium sulfite, either an oxathiazine 2,2-dioxide (4) and/or an oxazinedione (5). The ratio of (4) to (5) depends on the keto-enol equilibrium of the intermediate (2) and on the reaction conditions. 

Stelling (1928) found an absorption band in formaldehyde and acetone bisulfite addition compounds at 4992.0 A similar to that in sulfonic acids at 4992.2 and differing from that of metal alkyl (4996.0) and dialkyl sulfites (4997.7). He concluded from this that the sulfonic acid structure must be present. Raman spectral examinations of several aldehyde and ketone bisulfites by Caughlan and Tartar (1941) revealed the presence of a carbon-sulfur bond, possibly a carbon-hydroxyl bond, but no carbon doubly bonded to oxygen. This thus aided in discrediting both the tripartite molecule and the sulfurous acid ester structures. Sundman (1949) believes that formation of a stable monomolecular complex of boric acid and glucose bisulfite would be impossible if Schroeter s tripartite molecular structure were correct. His examinations of this complex led him to believe that its structure could be represented only by ... 

A similar concept as for carbonate ionophores has also been used for sulfite sensors. In this case, the well-known addition of sulfite to benzaldehyde derivatives by reversible formation of a covalent bond has been taken advantage of (Figure 29). However, while used for ion-selective optodes, this approach has not been tested for ISEs. Optodes based on the addition of H2O or alcohols to phenyl ketones have also been reported for the detection of humidity and alcohols in beverages, respectively, but because of the nonionic nature of these analytes, ISEs based on these ionophores are not feasible." ... 

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