Aldehydes => alkyl halides

The C-H bond in CBnHi2 and related anions can be metallated by butyllithium and then converted into C-substituted anions with aldehydes, alkyl halides, Ph3SiCl, and Ph2PCl.322-329 C-halogenated (F,Cl,Br, or I) derivatives are made from the C-copper derivative with (PhS02)2NF or the corresponding N-halosuccinimide.330 The l-Me-2,3>4,5,6,7,8,9,10,ll>12-Fu-CBii- anion is made from the reaction of the corresponding Fn anion with... 

The definition of what constitutes reactive or unstable functionality naturally varies somewhat, but there is also a good deal of consensus (aldehydes, alkyl halides, vinyl ketones, and so forth) [14,16-18]. 

Aldehydes Alkyl halides Calcium sulphate, magnesium sulphate, sodium sulphate. Calcium chloride, calcium sulphate, magnesium sulphate, phosphorus pentoxide, sodium sulphate. 

The hydroxyl groups on glycols undergo the usual alcohol chemistry giving a wide variety of possible derivatives. Hydroxyls can be converted to aldehydes, alkyl halides, amides, amines, azides, carboxylic acids, ethers, mercaptans, nitrate esters, nitriles, nitrite esters, organic esters, peroxides, phosphate esters, and sulfate esters (6,7). 

To capture electrophilic substrates such as acid halides, aldehydes, alkyl halides, isocyanates, and isothiocyanates, a variety of nucleophilic resins are commonly used. Some commercially available and representative examples are tris-(2-aminoethyl)amine (9), thiophenol (10), sulfonylhydrazide (11), triphenylphosphine (12), and methylthiourea (13) polymer resins (Fig. 6). 

Predict the products of reactions of amines with ketones and aldehydes, alkyl halides and tosylates, acid chlorides, sulfonyl chlorides, nitrous acid, and oxidizing agents. Propose mechanisms where appropriate. 

Flammable liquids may undergo a chemical reaction called polymerization, in which a large number of simple molecules, called monomers, combine to form long-chained molecule called a polymer. This process is used under controlled conditions to create plastics (see Fignre 5.17). AUcene hydrocarbon compounds and hydrocarbon derivatives, such as aldehydes, alkyl halides, and esters, and the aromatic hydrocarbon styrene may nndergo polymerization. There are other monomers that are flammable and can polymerize, but their primary hazard is poison. Monomers can be flammable liquids, flammable gases, and poisons. 

Condensation Reduction Dihydrazide Monosubstituted hydrazone of aldehyde Alkyl halide(s) 36,45,46 36, 37, 38... 

Alkylation of aldol type educts, e.g., /3-hydroxy esters, using LDA and alkyl halides leads stereoselectively to erythro substitution. The erythro threo ratio of the products is of the order of 95 5. Allylic and benzylic bromides can also be used. The allyl groups can later be ozonolysed to gjve aldehydes, and many interesting oligofunctional products with two adjacent chiral centres become available from chiral aldol type educts (G. Prater, 1984 D. Seebach, 1984 see also M. Nakatsuka, 1990, p. 5586). 

These compounds are sources of the nucleophilic anion RC=C and their reaction with primary alkyl halides provides an effective synthesis of alkynes (Section 9 6) The nucleophilicity of acetylide anions is also evident m their reactions with aldehydes and ketones which are entirely analogous to those of Grignard and organolithium reagents... 

Organozmc reagents are not nearly as reactive toward aldehydes and ketones as Grig nard reagents and organolithium compounds but are intermediates m certain reactions of alkyl halides... 

Because etiolate anions are sources of nucleophilic carbon one potential use m organic syn thesis IS their reaction with alkyl halides to give a alkyl denvahves of aldehydes and ketones... 

In practice this reaction is difficult to carry out with simple aldehydes and ketones because aldol condensation competes with alkylation Furthermore it is not always possi ble to limit the reaction to the introduction of a single alkyl group The most successful alkylation procedures use p diketones as starting materials Because they are relatively acidic p diketones can be converted quantitatively to their enolate ions by weak bases and do not self condense Ideally the alkyl halide should be a methyl or primary alkyl halide... 

Nitriles contain the —C=N functional group We have already discussed the two mam procedures by which they are prepared namely the nucleophilic substitution of alkyl halides by cyanide and the conversion of aldehydes and ketones to cyanohydrins Table 20 6 reviews aspects of these reactions Neither of the reactions m Table 20 6 is suitable for aryl nitriles (ArC=N) these compounds are readily prepared by a reaction to be dis cussed m Chapter 22... 

Section 20 18 Nitnles are prepared by nucleophilic substitution (8 2) of alkyl halides with cyanide ion by converting aldehydes or ketones to cyanohydrins (Table 20 6) or by dehydration of amides... 

Lithium dialkylamides are excellent bases for making ketone enolates as well Ketone enolates generated m this way can be alkylated with alkyl halides or as illus trated m the following equation treated with an aldehyde or a ketone... 

The dianions derived from furan- and thiophene-carboxylic acids by deprotonation with LDA have been reacted with various electrophiles (Scheme 64). The oxygen dianions reacted efficiently with aldehydes and ketones but not so efficiently with alkyl halides or epoxides. The sulfur dianions reacted with allyl bromide, a reaction which failed in the case of the dianions derived from furancarboxylic acids, and are therefore judged to be the softer nucleophiles (81JCS(Pl)1125,80TL505l). 

Dipotassium iron tetracartionyl in the synthesis ol aldehydes and ketones (tom alkyl halides. 

Aldehyde or ketone synthesis by reaction ol an alkyl halide with the so< un salt of 2-mtroalkanes. 

Synthesis of aldehydes from pnmary alkyl halides or tosylales, using dimethyl sulfoxide (OMSO). 

SOMMELET Aldehyde synthesis Aldehyde synthesis from primary alkyl halides with hexamethylene tetramine. 

This reaction illustrates a stereoselective preparation of (Z)-vinylic cuprates, which are very useful synthetic intermediates. They react with a variety of electrophiles such as carbon dioxide, epoxides, aldehydes, allylic halides, alkyl halides, and acetylenic halides they undergo... 

Sodium (metal). Used as a fine wire or as chips, for more completely drying ethers, saturated hydrocarbons and aromatic hydrocarbons which have been partially dried (for example with calcium chloride or magnesium sulfate). Unsuitable for acids, alcohols, alkyl halides, aldehydes, ketones, amines and esters. Reacts violently if water is present and can cause a fire with highly flammable liquids. 

Lithium aluminum hydride (LiAlH4) is the most powerful of the hydride reagents. It reduces acid chlorides, esters, lactones, acids, anhydrides, aldehydes, ketones and epoxides to alcohols amides, nitriles, imines and oximes to amines primary and secondary alkyl halides and toluenesulfonates to... 

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