Carbonyl compounds reaction with water

The reaction products with secondary amines could not be isolated in pure form, but since they are aminoacetals of the corresponding carbonyl compound, hydrolysis with water to LI is easily accomplished... 

It is claimed that a 1 1 mixture of (Z)- and (E)-CF3-CF CHF, obtained by removal of HF from CF3-CHF CHF2, upon reaction with butyl-lithium at low temperatures yields a lithium compound CFs-CFiCFLi which has lost its stereochemistry, since it reacts with carbonyl compounds, and with water, to yield only (Z)-derivatives. However, dehydrofluorination of the propane with aqueous KOH yields (Z)-CF3 CF CHF to the extent of some 95 %, so this report remains in doubt (see p. 179). 

The zwitterion (6) can react with protic solvents to produce a variety of products. Reaction with water yields a transient hydroperoxy alcohol (10) that can dehydrate to a carboxyUc acid or spHt out H2O2 to form a carbonyl compound (aldehyde or ketone, R2CO). In alcohoHc media, the product is an isolable hydroperoxy ether (11) that can be hydrolyzed or reduced (with (CH O) or (CH2)2S) to a carbonyl compound. Reductive amination of (11) over Raney nickel produces amides and amines (64). Reaction of the zwitterion with a carboxyUc acid to form a hydroperoxy ester (12) is commercially important because it can be oxidized to other acids, RCOOH and R COOH. Reaction of zwitterion with HCN produces a-hydroxy nitriles that can be hydrolyzed to a-hydroxy carboxyUc acids. Carboxylates are obtained with H2O2/OH (65). The zwitterion can be reduced during the course of the reaction by tetracyanoethylene to produce its epoxide (66). 

Chan and Li reported that conjugated 1,3-butadienes were produced in moderate yields when carbonyl compounds reacted with 1,3-dichloropropene and zinc in water (Eq. 8.29).61 The use of 3-iodo-1-chloropropene instead of 1,3-dichloropropene greatly improved the yields. When the reactions were interrupted after their initial allyla-tions, subsequent base treatment of the intermediate compounds produced vinyloxiranes in high yields. Similarly, reactions of carbonyl compounds with 3-iodo-2-chloromethyl-l-propene followed by base treatment produced 2-methylenetetrahydrofurans (Eq. 8.30).62 Thus, the 3-iodo-2-chloromethyl-l-propene served as a novel trimethylene-methane equivalent.63... 

Mechanism The reaction of the enol form of the carbonyl compound A with selenium dioxide gives selenous enol ester B. The oxidative rearrangement of selenous enol ester B gives C. Loss of selenium and water from C gives the dicarbonyl compound (Scheme 7.16). 

Aromatic and aliphatic carbonyl compounds condense with glycols, such as ethylene, propylene, and trimethylene glycols, to form cyclic acetals p-toluenesulfonic acid has proved to be an excellent catalyst. As before, the water formed in these reactions is conveniently removed by an azeotropic distillation with benzene. Representative aldehydes and ketones that undergo this acetalization include acetone, cyclohexanone, pinacolone, acetophenone, benzophenone, n-heptaldehyde. 

Electrolysis of benzothiete sulfone 269 yields the phenylmethanesulfinate anion (major) and the o-toluenesulfinate anion (minor).Thermolysis 618,619 gj. photolysis of thiete 1,1-dioxides proceeds via ring-opening to vinyl sulfines, for example. 288, which have been trapped by reaction with water, phenol,methanol, or norbornenes. These intermediates may recyclize to unsaturated sultines (cyclic sulfinate esters) (e.g., 289) or lose sulfur monoxide to give mainly the trans isomers of a,j3-unsaturated carbonyl compounds (e.g., 290). Mass spectra also indicate the formation of unsaturated sultines. ... 

Properties and reactions of nitramines Secondary nitramines are neutral, primary nitramines form salts with bases, but an excess of alkali often causes decomposition to the carbonyl compound, nitrogen, and water. Secondary nitramines and aqueous alkali afford nitrous acid, aldehyde, and primary amine. Acids decompose primary aliphatic nitramines with formation of nitrous oxide in a reaction that has not yet been clarified thus these compounds cannot be hydrolysed by acid to amines in the same way as nitrosamines, although, like the latter, they can be reduced to hydrazines. Primary and secondary aromatic nitramines readily rearrange to C-nitroarylamines in acid solution. Most nitramines decompose explosively when heated, but the lower aliphatic secondary nitramines can be distilled in a vacuum. 

Thermal or photolytic decomposition of a diazo compound which has a carbonyl group a to the diazo group often yields a ketene, which can be trapped by conventional techniques, such as reaction with water to give a carboxylic acid . 

In carbonyl condensation reactions the enolate or enol of one carbonyl compound reacts with the carbonyl group of another to join the two reactants. As part of the process, a new molecule that is derived from them condenses (forms). Often this molecule is that of an alcohol or water. The main types of condensation reactions we shall study are the Claisen condensation and the aldol condensation. Aldol condensations are preceded mechanistically by aldol additions, which we shall also study. The name aldol derives from the fact that aldehyde and alcohol functional groups are present in the products of many aldol reactions. 

The aldol reaction is one of the most powerful methods for C-C bond formation. It was independently discovered by Wurtz and Borodin, the famous composer, in 1872 [1], Nowadays, like Borodin s music, this reaction is considered a classic in organic chemistry. In the aldol reaction, an enolizable carbonyl compound reacts with another aldehyde or ketone, leading to a (3-hydroxy carbonyl compound called an aldol (Scheme 3.1). Subsequently, it can eliminate water to form an a,(3-unsaturated carbonyl compound. 

Under acidic or basic conditions, the rate of hydrolysis is enhanced. Under acidic conditions, the hydrolysis involved protonation of the in-chain oxygen atom of the ester function followed by reaction with water to produce hydroxyl and carboxyl end groups compounds. Under basic conditions, the hydroxide anion attacks the carbonyl oxygen atom to produce same compounds. The hydrolysis reaction can be followed by measuring the increase in the concentration of carboxyl ends with time by using classical end group analysis (14,15). 

FIGURE 16.49 Continuation of reactions from Figure 16.48. In the reaction with water, loss of a proton leads to the recovered carbonyl compound. In the alcohol reaction, there is no proton to be lost, and a second molecule of alcohol adds to give an acetal. In the reaction with amine, loss of a proton leads to an imine. 

As the zero-valent indium species is regenerated by either zinc or aluminum, a catalytic amount of InCls, together with either zinc or aluminum, could be utilized in the allylation of carbonyl compounds in tetrahydrofuran-water mixture. The presence of water was found to be effective in suppressing undesired side-reactions (Araki et al, 1992). 

In an aldol reaction, an enolizable carbonyl compound reacts with another carbonyl compound that is either an aldehyde or a ketone. The enolizable carbonyl compound, which must have at least one acidic proton in its a-position, acts as a nucleophile, whereas the carbonyl active component has electrophilic reactivity. In its classical meaning the aldol reaction is restricted to aldehydes and ketones and can occur between identical or nonidentical carbonyl compounds. The term aldol reaction , in a more advanced sense, is applied to any enolizable carbonyl compounds, for example carboxylic esters, amides, and carboxylates, that add to aldehydes or ketones. The primary products are always j5-hydroxycarbonyl compounds, which can undergo an elimination of water to form a,j5-unsaturated carbonyl compounds. The reaction that ends with the j5-hydroxycarbonyl compound is usually termed aldol addition whereas the reaction that includes the elimination process is denoted aldol condensation . The traditional aldol reaction [1] proceeds under thermodynamic control, as a reversible reaction, mediated either by acids or bases. 

This oxidation reaction with water is understood by the sequence hydroxypalladation followed by carbonyl generation via 1,2-hydride shift (eq 4). It has been confirmed that no incorporation of deuterium occurs when the reaction is carried out in D2O and that all hydrogens of the alkene are retained in the carbonyl compound, which is clearly indicative of the hydride shift. 

One of the first variations of the Wittig reaction was initially reported by Homer and coworkers and rapidly followed by an initial report by Wadsworth and Emmons. These examples made use of phosphine oxide/phosphonate derivatives of the ylides first reported by Wittig and are now collectively known as the Homer-Wadsworth-Emmons reaction (HWE). Ylide formation occurs upon deprotonation of dialkoxy phosphonate 31 and alkene 32 is formed from carbonyl compound 30 with loss of the corresponding phosphate derivative 33. The use of this variation has advantages over the eonventional version a) phosphonate carbanions are known to be more nucleophilic due to decreased stabilization by valence shell expansion of the phosphorous atom, thus are able to react with a wider diversity of carbonyl compounds, b) the phosphorous-based product of the reaction, a water-soluble phosphate, allows for a greater ease of reaction work-up. c) the enhanced reactivity of the phosphonate permits direct derivitization of the reagent, d) the Arbuzov reaction allows for ready preparation of the desired phosphonate. 

Interpretation of the EXAFS of [Os3(CO)i2] absorbed on silica in terms of a structure [Os3(CO)ioH(OS=)] has been confirmed by comparison with [OS3-(CO)ioH(OSiPh3)], which was prepared from the reaction between [Os3(CO)i2] and Si(OH)Ph3. The same species is formed by physisorption of [Os3(CO)ioH3] and of [Os6(CO)i8l on silica. Carbon monoxide inhibits the transformation to [Rh8(CO)i8] which occurs when [Rh4(CO)i2] is chemisorbed on highly divided silica. Both [Rh4(CO)i2] and [Rh8(CO)x8] are converted to high nuclearity rhodium particles when the chemisorbed carbonyls are treated with water vapour, but surface-bound [Rh(CO)2(OSi=)] is formed when the chemisorbed polynuclear carbonyls are treated with oxygen gas. The molecular compounds [Rh4(CO)i2] and [Rh8(CO)i8] can be regenerated in that sequence when [Rh(CO)2(OSi=)] is treated with CO. In this context, the observation that Na2[M(CO)5] reduces CO2 to form [M(CO)8] (M=Mo, W) and carbonate ion may provide a model for the surface process. ... 

The most commonly used protected derivatives of aldehydes and ketones are 1,3-dioxolanes and 1,3-oxathiolanes. They are obtained from the carbonyl compounds and 1,2-ethanediol or 2-mercaptoethanol, respectively, in aprotic solvents and in the presence of catalysts, e.g. BF, (L.F. Fieser, 1954 G.E. Wilson, Jr., 1968), and water scavengers, e.g. orthoesters (P. Doyle. 1965). Acid-catalyzed exchange dioxolanation with dioxolanes of low boiling ketones, e.g. acetone, which are distilled during the reaction, can also be applied (H. J. Dauben, Jr., 1954). Selective monoketalization of diketones is often used with good success (C. Mercier, 1973). Even from diketones with two keto groups of very similar reactivity monoketals may be obtained by repeated acid-catalyzed equilibration (W.S. Johnson, 1962 A.G. Hortmann, 1969). Most aldehydes are easily converted into acetals. The ketalization of ketones is more difficult for sterical reasons and often requires long reaction times at elevated temperatures. a, -Unsaturated ketones react more slowly than saturated ketones. 2-Mercaptoethanol is more reactive than 1,2-ethanediol (J. Romo, 1951 C. Djerassi, 1952 G.E. Wilson, Jr., 1968). 

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