Aldehydes, bisulfite addition products

Not-Strike may have seen. But what Dr. Quack did that SWINS did not was use the bisulfite test with positive results. What does that mean It means that some doublebonded oxygen was formed, unless Dr. Quack was fibbing to us, It cannot have been a propiophenone (don t ask) because propiophenones cannot form the bisulfite addition product. Could an aldehyde have formed (don t ask) Maybe. But highly unlikely considering the mechanism of the reaction. 

An alternate method of producing the 21-hydroxy-20-ketone consists in lithium aluminum hydride reduction of the dimethyl acetal, hydrolysis to the 20-hydroxy-21-aldehyde and rearrangement, preferably via the bisulfite addition product... 

Bisulfite addition products are formed from aldehydes, methyl ketones, cyclic ketones (generally seven-membered and smaller rings), a-keto esters, and isocyanates, upon treatment with sodium bisulfite. Most other ketones do not undergo the reaction, probably for steric reasons. The reaction is reversible (by treatment of the addition product with either acid or base ) and is useful for the purification of the starting compounds, since the addition products are soluble in water and many of the impurities are not. ... 

Frequently, it is the bisulfite addition product that is treated with CN. This method is especially useful for aromatic aldehydes, since it avoids competition from the benzoin condensation. If desired, it is possible to hydrolyze the cyanohydrin in situ to the corresponding a-hydroxy acid. This reaction is important in the Kiliani-Fischer method of extending the carbon chain of a sugar. 

This is probably the single most important material used by the fragrance industry. Several million pounds are used annually, mainly in soaps and detergents. The principal method of manufacture shown in Figure 10 is by hydration of citronellal via the bisulfite addition product (2). The aldehyde moiety must be protected before hydration. A second manufacturing process starts with citronellol which is hydrated under acid conditions. The primary alcohol end of the molecule is then dehydrogenated catalytically or by oxidation to the aldehyde. 

Condensation of sodium salts of acinitroalkanes with the sodium bisulfite addition products of aldehydes in the presence of trace of alkali or weak acid also gives nitro alcohols as reported byKamlet o. 

Benzal chlorides. Benzaldehyde or the bisulfite addition product reacts with thionyl chloride and DMF at -10 20° to form benzal chloride, QHsCHCU, in 88% yield. Newman favors structure 1 for the Vilsmeier complex involved in this reaction. This reaction is general for aromatic aldehydes and a, -unsaturated aldehydes. The reaction is not observed with diaryl ketones. 

Bisulfite addition products are readily formed at wine pHs (1, 23, 24). The bisulfite addition product is thought to be a more sensory-neutral compound and may be exploited by winemakers as a means of decreasing the aldehydic character of wines (1). Bisulfite addition has also been used to mask the stale flavor of beer which is thought to be largely due to the formation of trans-l-noneml (25). Kaneda et al. (25) used HPLC with fluorescent detection of an o-phthalaldehyde derivative to quantitate and identify individual aldehyde-bisulfite products, however, only acetaldehyde-bisulfite adducts were observed in commercial beers with this method. Hydrolysis of the adducts occurs at pHs greater than 8, therefore by adjusting the pH prior to analysis, total aldehydes (free plus bisulfite bound) can be estimated. At low pHs accurate estimation of free aldehydes is complicated however, by analysis conditions which alter the equilibrium between bound and free forms (temperature, dilution, solvent extraction, analysis time, etc.). 

The sodium bisulfite addition products of aldehydes have been converted by the action of potassium cyanide and an amine to a-alkylamino cyanides. The procedure is best suited for obtaining amino nitriles derived from formaldehyde and simple amines and is illustrated in the preparation of diethylaminoacetonitrile (90%). ... 

Bisulfite Test. Follow the procedure on page 313, Chapter 30. Nearly all aldehydes and most methyl ketones form solid, water-soluble bisulfite addition products. 

Sodium bisulfite adds to most aldehydes and to many ketones (especially methyl ketones) to form bisulfite addition products ... 

Crude bromophenanthrene prepared by the bromination of technical (90%) phenanthrene and purified by distillation only was used by the submitters in this preparation. The an-thracene-9-aldehyde, which may be formed from the anthracene present as an impurity in 90% phenanthrene, does not form a sodimn bisulfite addition product and so will not contaminate the phenanthrene-9-aldehyde. The checkers used 9-bromophe-nanthrene, m.p. 54-56° (p. 20), exclusively, but without any advantage in yield. The submitters report yields of 55-60% from pure 9-bromophenanthrene. 

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 ... 

Aldehydes. Conversion to solid sodium bisulfite addition product with excess reagent, removal of nonaldehydic material by washing with alcohol or ether, and regeneration usually with acid, base, or sodium carbonate, provides a convenient method of purification. Examples syringic aldehyde, n-hexaldehyde. ... 

Henry reaction. Formation of nitroalcohols by an aldol-type condensation of nitroparaffins with aldehydes in the presence of base (Henry) or by the condensation of sodium salts of aci nitroparaffi ns with the sodium bisulfite addition products of aldehydes in the presence of a trace of alkali or weak acid (Kamlet). Widely used in sugar chemistry. 

The carbohydrates failed to undergo certain reactions that were typical of aldehydes. Although the hexoses and pentoses were readily oxidized at C-1 under mild alkaline conditions, they did not give a positive result with the Schiff test (reaction with basic fuchsin), and they did not form bisulfite addition products, reactions that are typical of aldehydes. The cyanohydrin and phenylhydrazine reactions also went much more slowly than they did for other a-hydroxy aldehydes. 

The material is triturated with saturated sodium bisulfite solution (2 cc. per gram), and after about three hours the pasty mixture is filtered with suction. The addition product is washed with absolute alcohol and then with ether and transferred to a flask fitted for steam distillation. Excess sodium carbonate solution is added and the aldehyde is distilled in a current of steam. 

Possible toxic reactions of sulfur dioxide are also indicated in Table I. The reaction of bisulfite with aldehydes has a classic position in biochemistry since Neuberg demonstrated in 1918 that the products of fermentation by yeast were altered by the addition of sodium sulfite, which caused the production of equal amounts of the bisulfite addition compound of acetaldehyde and of glycerol. This was concomitant with the blockage of conversion of acetaldehyde to ethanol. Addition compounds can also be formed with quinones and with ,/ -unsaturated compounds. None of these reactions has been adequately assessed as a possible contributor to toxicity. 

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 products are useful for two reasons. They are usually crystalline and so can be used to purify liquid aldehydes by recrystallization. This is of value only because this reaction, like several you have met in this chapter, is reversible. The bisulfite compounds are made by mixing the aldehyde or ketone with saturated aqueous sodium bisulfite in an ice bath, shaking, and crystallizing. After purification the bisulfite addition compound can be hydrolysed back to the aldehyde in dilute aqueous acid or base. 

The adducts formed from amine bisulfites and aldehydes are readily purified by crystallization from organic solvents and, like the sodium bi sulfite addition products, are readily decomposed by the action of dilute acids. 

The bisulfite ion is a strong nucleophile but a weak acid. It will attack the unhindered carbonyl group of an aldehyde or methyl ketone to form an addition product ... 

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