Amides reaction with aldehydes

P-Hydroxy amides. Cerium(III) enolates of amides show better reactivities than the Li enolates toward ketones and aldehydes. Reaction with camphor gives >94% yield of the aldol. 

There is a rather useful reaction with amides. Organolithium reagents react with DMF to give aldehydes.. An example is the reaction of 231 with s c-butyllithium to give the aryl-lithium reagent (see sec. 8.5.F for directed ortho metalation reactions). Subsequent reaction with DMF and hydrolysis gave a 91% yield of aldehyde 232 in Yamaguchi s synthesis of the radulanins. ... 

Hydroformylation (0x0 reaction) affords aldehyde and an amide is added to the aldehyde under these reaction conditions to produce an acylamino acid as shown in eq. (17.32). This reaction is named the Wakamatsu reaction in which an amino acid is produced directly from an olefin [46,77]. Cobalthydrocarbonyl (HCo(CO)4) is a strong acid as the aldehyde reacts with amide to afford an aminoalcohol, and a dehydration condensation with HCo(CO)4 forms a carbon-Co bond, and carbonylation and hydrolysis to produce the acylamino acid [46,77]. The carbonylation... 

K[HSi(OEt)4] reduces aldehydes, ketones, and esters in the absence of added catalyst. Treatment of nonenolizable amides yields the corresponding aldehydes. Reaction with 1 equiv of isocyanate in diethyl ether or THF leads quantitatively to the potassium imidate, which can be quenched in situ (eq Furthermore, use of an excess of aryl isocyanate yields to the corresponding isocyanurate. ... 

Jacobi von Wangelin A, Neumann H, Gordes D et al (2003) Multicomponent coupling reactions for organic synthesis chemoselective reactions with amide-aldehyde mixtures. Chem Eur J 9 4286 294... 

Now let s draw the forward scheme. 1,1-Dibromopentane is converted to 1-pentyne by reaction with excess sodium amide (to afford double elimination followed by deprotonation of the resulting alkyne), followed by aqueous woikup to protonate the terminal aUcynide. 1-Pentyne is converted to the aldehyde via hydroboration/oxidation. Subsequent reaction with sodium acetylide, followed by aqueous woikup, produces an alcohol. Reduction with H2 and Lindlar s catalyst converts the alkyne group to an alkene group. Ozonolysis converts the alkene to an aldehyde. Reaction with concentrated acid allows for elimination of the alcohol, producing the target compound. 

In the reverse reaction, thioheteroaryl amides reacted under reflux in alcohol with haloketones or aldehydes to give the corresponding 2-heteroarylthiazole derivatives (238, 271, 482, 550, 751, 765, 776, 781). 2,2 -Bithiazoles (4,4 -disubstituted) have been obtained in 80 to 90% yield by cyclocondensation of 1 mole rubeanic acid with 2 moles of a-bromoketones in polyphosphoric acid at 95 to 135 C (780). Some multiheteroaryl substituted thiazoles have been also reported (704). 

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). 

When the enamine is in conjugation with a carbonyl function, as in a-aminomethylene aldehydes (528,529), ketones (530), or esters (531), a Michael addition is found in vinylogous analogy to the reactions of amides. An application to syntheses in the vitamin A series employed a vinyl lithium compound (532). 

Fc(CO)5] reacts similarly. Aldehydes and ketones can also be obtained from N,N-disubstituted amides, and symmetrical ketones are formed by reaction with CO ... 

While the majority of examples of the Fiesselmann reactions found in the literature involve thioglycolic acid or the corresponding thioglycolates, the scope of this reaction has been expanded to a variety of other a-mercaptocarbonyl derivatives. Some examples include a-mercapto aldehydes, ketones,and amides. Notably, when compound 33 is treated with 2-mercaptoacetamide, compound 34 was produced in 48% yield. ... 

A -Chloromethylamine attacks ketones in alkaline solution with formation of oxaziranes with cyclohexanone, compound 17 is produced in 50% yield. The reaction with aldehydes with zV-chloromethyl-amine yields predominantly acid amides. However, oxaziranes are also produced here as by-products. From benzaldehyde and A -chloro-methylamine, 2-raethyl-3-phenyloxazirane (15) was obtained in 10% yield. 

McCluskey et al. have also used [BMIM][BF4] as a solvent for the allylation of aldehydes and Weinreb amides [56]. Similar diastereoselectivities and similar or slightly lower yields were obtained in this ionic liquid, compared with reactions carried... 

Reaction with water to yield a carboxylic acid Reaction with an alcohol to yield an ester Reaction with ammonia or an amine to yield an amide Reaction with a hydride reducing agent to yield an aldehyde or an alcohol... 

Many types of carbonyl compounds, including aldehydes, ketones, esters, thioesters, acids, and amides, can be converted into enolate ions by reaction with LDA. Table 22.1 lists the approximate pKa values of different types of carbonyl compounds and shows how these values compare to other acidic substances we ve seen. Note that nitriles, too, are acidic and can be converted into enolate-like anions. 

A key step in the synthesis of the spiroketal subunit is the convergent union of intermediates 8 and 9 through an Evans asymmetric aldol reaction (see Scheme 2). Coupling of aldehyde 9 with the boron enolate derived from imide 8 through an asymmetric aldol condensation is followed by transamination with an excess of aluminum amide reagent to afford intermediate 38 in an overall yield of 85 % (see Scheme 7). During the course of the asymmetric aldol condensation... 

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