Sulfite addition products

Exercise 16-18 Sodium hydrogen sulfite addition products are decomposed to the parent carbonyl compounds when treated with mild acid or mild alkali. Write equations for the reactions involved and explain why the substances are unstable both in acid and 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 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... 

Miscellaneous. In ore flotation, sodium sulfite functions as a selective depressant. In textile processing, sodium sulfite is used as a bleach for wood (qv) and polyamide fibers and as an antichlor after the use of chlorine bleach. Synthetic appHcations of sodium sulfite include production of sodium thiosulfite by addition of sulfur and the introduction of sulfonate groups into dyestuffs and other organic products. Sodium sulfite is useful as a scavenger for formaldehyde in aminoplast—wood compositions, and as a buffer in chrome tanning of leather. 

A detailed procedure for the use of MCPBA recently appeared in Reagents for Organic Synthesis by Fieser and Fieser. The commercially available MCPBA (Aldrich) is 85% pure the contaminant, m-chlorobenzoic acid, can be removed by washing with a phosphate buffer of pH 7.5. The epoxidation is usually performed as follows a solution of 3 -acetoxy-5a-androst-16-ene (2.06 g, 6.53 mmoles) in 25 ml of chloroform (or methylene dichloride) is chilled to 0° in a flask fitted with a condenser and drierite tube and treated with a solution of commercial MCPBA (1.74 g, 20% excess) in 25 ml chloroform precooled to the same temperature. The mixture is stirred and allowed to warm to room temperature. After 23 hr (or until TLC shows reaction is complete) the solution is diluted with 100 ml chloroform and washed in sequence with 100 ml of 10% sodium sulfite or sodium iodide followed by sodium thiosulfate, 200 ml of 1 M sodium bicarbonate and 200 ml water. The chloroform extract is dried (MgS04) and evaporated in vacuo to a volume of ca. 10 ml. Addition of methanol (10 ml) followed by cooling of the mixture to —10° yields 0.8 gof 16a,17a-epoxide mp 109.5-110°. Additional product can be obtained by concentration of the mother liquor (total yield 80-90%). 

F. Sodium Bisulfite Addition Product Formation The red color of aminochrome solutions is rapidly discharged by the addition of sodium bisulfite with the formation of pale-yellow fluorescent solutions. The reactions of adrenochrome with sulfites and bisulfites have been the subject of several previous reports.12, 102.109.118,119.123,128,148.182.155. 158,173-177 Although it was originally... 

Consideration of reasonable mechanisms for producing formic acid from an aldose led to the hypothesis that the sugar forms an addition product with the hydroperoxide anion, comparable with an aldehyde sulfite or the addition product of aldoses with chlorous acid (52). The intermediate product (12) could decompose by a free-radical or an ionic mechanism. In the absence of a free-radical catalyst, the ionic mechanism of Scheme VIII seems probable. By either mechanism the products are formic acid and the next lower sugar. The lower sugar then repeats the process, with the result that the aldose is degraded stepwise to formic acid. Addition of the hydroperoxide anion to the carbonyl carbon is in accord with its strong nucleophilic character (53) and with certain reaction mechanisms suggested in the literature (54) for related substances. 

The addition products often are nicely crystalline solids that are insoluble in excess concentrated sodium hydrogen sulfite solution. Whether soluble or insoluble, the addition products are useful for separating carbonyl compounds from substances that do not react with sodium hydrogen sulfite. 

However, it fails to give a hydrogen sulfite addition compound and, although it will react with amines (RNH2), the products are not the expected Schiff s... 

Sulfite addition in water can be treated but here it seems necessary to use nine explicit waters solvating the C-O- in the initial product of sulfite addition in order to avoid breakdown of the adduct. Clearly it would be better to include a large number of waters in every case but the cost of the optimizations goes up as the number of waters increases. From a practical perspective it is better to allow a bit of empiricism to find the number of waters needed to reliably give a good result. This reaction is still under investigation as we seek to find a general way to carry out structure optimizations with reaction intermediates that have a lifetime in solution but are unstable in the gas phase unless explicitly solvated. 

Cessation of fermentation is one of the technical problems in botrytized wine production that needs further research and development. Dimethyldicarbonate (DMDC) is now considered a reliable inhibitor which could replace some of the S02. Although DMDC has proven suited for treating wines especially just before bottling, its use in Sautemes production has been investigated (Divol et al., 2005). The results showed that DMDC at a rate of 100-200 mg/1 stopped fermentation but did not replace the antioxidant functions of SO2. Sulfite addition was necessary to limit wine oxidation and yeast reactivation. 

The effects of the above reactions on the receiving streams are a reduction of dissolved oxygen and an increase in BOD and COD. In addition, the right-hand sides of the reactions, except those for sodium sulfite, indicate production of the hydrogen ion. Thus, there is the possibility of a decrease in pH of the receiving streams. 

Heteroatomic nucleophiles which also have been shown to undergo addition across the 3,4-double bond of quinazolines 5 and with which the addition products 6 were isolated include the methoxide anionand sodium hydrogen sulfite.(For addition of sodium hydrogen sulfite and hydrazine at the 4-position of quinazoline 3-oxides with concomitant deoxygenation of the A(-oxide group, cf p 105.) Equilibrium and rate constants have been determined at 25 °C for the covalent addition of water, the bisulfite ion, hydroxylamine, urea, 2-sulfanylethanol, and hydrogen sulfide to the 3,4-bond of the quinazoline cation. ... 

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). 

Cyclic sulfites or cyclic sulfates having a C=C bond either in the ring or on the side chain undergo smooth addition of electrophiles to furnish a good yield of the product. For example, enediol cyclic sulfite 75 undergoes addition of 0,0-diethyl dithiophosphate to furnish a high yield of addition product 76 (84CHEC851) [Eq. (22)]. 

The normal reaction products—nitrogen, water, and a small amount of NFls—are all volatile, and, unlike sulfite addition, no dissolved solids accumulate in the treated water. 

This method is based on the quantitative liberation of sodium hydroxide when formaldehyde reacts with sodium sulfite to form the formaldehyde-bisulfite addition product. The volume of sample may be varied depending on the formaldehyde content but the solution to be titrated must contain excess sodium sulfite. Formaldehyde solutions containing substantial amounts of acid or base must be neutralized before analysis. 

This equilibrium is dependent on pH, with the dominant species at wine pH (3 to 4) being the bisulfite anion (Fig. 5.1). Besides being in equilibrium with the molecular and sulfite species, bisulfite also exists in free and bound forms. Here, the molecule will react with carbonyl compounds (e.g., acetaldehyde), forming addition products or adducts such as hydroxysulfonic acids. 

In some reactions, thiosulfates and notably selenosulfates behave as though they are loose addition products of sulfite ion and sulfur or selenium. In contrast to thiosulfate, which remains totally unaltered, selenosulfate reacts with formaldehyde as though it consists of a mixture of selenium and sulfite, i.e., aldehyde-bisulfite is formed and free selenium is precipitated. ... 

Vitamin Kj and its water soluble forms, such as salts or complexes of its addition product with sodium hydrogen sulfite (trihydrate of sodium salt), and its complex with nicotinamide (5-48) or with... 

When maleic acid, esters, etc., are treated with sodium sulfite or bisulfite, an addition product is formed. Thus, when maleic acid sodium salt is treated with sodium bisulfite, trisodium sulfosuccinate is formed... 

---