With aldehydes or ketones

Methylenebispiperidine was used as a source of formaldehyde to convert 2-aminobenzenecarboxanilide to 3-phenyl-l,2-dihydroquinazolin-4-one in excellent yield.273 

Finally, acetone and 2-aminobenzamide, refluxed 15 hr in 1 N hydrochloric acid, produced 2,3-dimethyl-l,2-dihydroquinazolin-4-one (no yield given).276 Apparently, aldehydes and ketones have yet to be tried on a 7t-deficient host ring. 

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Reagent B is valuable for use with aldehydes or ketones which are insoluble in water, and therefore unsuitable for treatment with Reagent A cf. benzaldehyde, p, 342 benzophenone, p. 346). It is much more concentrated than A, and consequently can be more readily used for the isolation and purification of the required hydra2one. 

Cycloaddition of COj with the dimethyl-substituted methylenecyclopropane 75 proceeds smoothly above 100 °C under pressure, yielding the five-membered ring lactone 76. The regiocheraistry of this reaction is different from that of above-mentioned diphenyl-substituted methylenecyclopropanes 66 and 67[61], This allylic lactone 76 is another source of trimethylenemethane when it is treated with Pd(0) catalyst coordinated by dppe in refluxing toluene to generate 77, and its reaction with aldehydes or ketones affords the 3-methylenetetrahy-drofuran derivative 78 as expected for this intermediate. Also, the lactone 76 reacts with a, /3-unsaturated carbonyl compounds. The reaction of coumarin (79) with 76 to give the chroman-2-one derivative 80 is an example[62]. 

The primary and secondary alcohol functionahties have different reactivities, as exemplified by the slower reaction rate for secondary hydroxyls in the formation of esters from acids and alcohols (8). 1,2-Propylene glycol undergoes most of the typical alcohol reactions, such as reaction with a free acid, acyl hahde, or acid anhydride to form an ester reaction with alkaU metal hydroxide to form metal salts and reaction with aldehydes or ketones to form acetals and ketals (9,10). The most important commercial appHcation of propylene glycol is in the manufacture of polyesters by reaction with a dibasic or polybasic acid. 

Reactions. Heating an aqueous solution of malonic acid above 70°C results in its decomposition to acetic acid and carbon dioxide. Malonic acid is a useful tool for synthesizing a-unsaturated carboxyUc acids because of its abiUty to undergo decarboxylation and condensation with aldehydes or ketones at the methylene group. Cinnamic acids are formed from the reaction of malonic acid and benzaldehyde derivatives (1). If aUphatic aldehydes are used acryhc acids result (2). Similarly this facile decarboxylation combined with the condensation with an activated double bond yields a-substituted acetic acid derivatives. For example, 4-thiazohdine acetic acids (2) are readily prepared from 2,5-dihydro-l,3-thiazoles (3). A further feature of malonic acid is that it does not form an anhydride when heated with phosphorous pentoxide [1314-56-3] but rather carbon suboxide [504-64-3] [0=C=C=0], a toxic gas that reacts with water to reform malonic acid. 

Most processes in use in the 1990s make pyridines by condensation of ammonia with aldehydes or ketones either in the vapor phase or in the Hquid phase. These processes are based on the pioneering work of Chichibabin (3). Commercial practice of that process was not reali2ed until some 50 years after its discovery (74,75). 

HORNER - WADSWORTH - EMMONS Olelination Wittig type reaction of ptwsptionale stabilized carbanions with aldehydes or ketones to form olefins... 

Olefin synthesis Irom phosphorane ylides (e g 3) with aldehydes or ketones cis olelins predominate in aliphatic systems trans m coniugated olefins... 

Mixtures of anhydrous hydrogen fluoride and tetrahydrofuran are successfully used as fluorinating agents to convert 1,1,2-trifluoro-l-allcen-3-ols, easily prepared from bromotrifluoroethene via lithiation followed by the reaction with aldehydes or ketones, to 1,1,1,2-tetrafluoro-2-alkenes The yields are optimal with a 5 1 ratio of hydrogen fluoride to tetrahydrofuran The fluorination reaction involves a fluonde lon-induced rearrangement (Sf,j2 mechanism) of allylic alcohols [65] (equation 40)... 

Despite the increasing information on the photochemistry of 2,4-dienones and other unsaturated ketones, as well as on the ring-chain valence isomerism of halogen-substituted pyran and dihydi opyran systems,the data are still very scarce. The intermediate formation of pyrans valence-isomeric with unsaturated carbonyl compounds in the pyridine syntheses based on reactions of ammonia with aldehydes or ketones, advocated by various authors (cf. Section II,B,2,f), is still rather speculative. (See also Section II,B,2,e for the valence isomerism of 5-chloro-2,4-dienones with pyrylium chlorides.)... 

Alkenes (olefins) from reaction of phosphonium ylides with aldehydes or ketones... 

The initial step is the formation of hydrazone 2 by reaction of hydrazine with aldehyde or ketone 1 ... 

Triphenylphosphine reacts with alkyl halides to form alkyltriphenylphosphonium salts. Upon reaction with strong bases, the salts release a proton to form an ylide (alkylidenetriphenylphosphorane), which is capable of reacting with aldehydes or ketones providing an unambiguous route to olefins. Since there are virtually no... 

Reaction of Primary or Secondary Amides with Aldehydes or Ketones... 

In the base-catalyzed condensation of diethyl ethylsulfonylmethylphosphate with aldehydes or ketones, the corresponding a, /1-unsaturated sulfones were obtained in good yields297,364,365. 

Dimetal derivatives 283 of alkyl and benzyl phenyl sulfones were found to react with aldehydes or ketones to give a, /J-unsaturated phenyl sulfones 284 in good yields366. 

By reaction of PC13 with aldehyde or ketone in the presence of acetic acid followed by hydrolysis, a-hydroxyalkylphosphonic acids are obtained, according to Eqs. (57)-(59). 

Cyclic acetals formed by the reaction of saccharides or saccharide derivatives with aldehydes or ketones are named in accordance with 2-Carb-24.1, bivalent substituent names (formed by general organic nomenclature principles) being used as prefixes. In indicating more than one cyclic acetal grouping of the same kind, the appropriate pairs of locants are separated typographically when the exact placement of the acetal groups is known. 

The condensation of aromatic rings with aldehydes or ketones is called hydroxy-alkylation. The reaction can be used to prepare alcohols, though more often the alcohol initially produced reacts with another molecule of aromatic compound (11-12) to give diarylation. For this the reaction is quite useful, an example being the preparation of l,l,l-trichloro-2, 2-bis (p-Chlorophenyl) ethane (DDT) ... 

Both alcohols and phenols add to ketenes to give carboxylic esters (R2C=C= O+ROH —> R2CHC02R). This has been done intramolecularly (with the ketene end of the molecule generated and used in situ) to form medium- and large-ring lactones. In the presence of a strong acid, ketene reacts with aldehydes or ketones (in their enol forms) to give enol acetates. 

Lithiated allylic carbamates (35) (prepared as shown) react with aldehydes or ketones (R C0R ), in a reaction accompanied by an allylic rearrangement, to give (after hydrolysis) y-hydroxy aldehydes or ketones. The reaction is called the homoaldol reaction, since the product is a homolog of the product... 

This dimerization is so rapid that ketene does not form P-lactones with aldehydes or ketones, except at low temperatures. Other ketenes dimerize more slowly. In these cases the major dimerization product is not the P-lactone, but a cyclobutanedione (see 15-61). However, the proportion of ketene that dimerizes to p-lactone can be increased by the addition of catalysts such as triethylamine or triethyl phosphite. Ketene acetals R2C=C(OR )2 add to aldehydes and ketones in the presence of ZnCl2 to give the corresponding oxetanes. ... 

Alkylation of enamines Addition of amines to triple-bond compounds Addition of amines to aldehydes or ketones Reaction between Grignard reagents and formamides Reaction of phosphonates with aldehydes or ketones... 

Condensation of formaldehyde with aldehydes or ketones (Tollens)... 

Reaction of halophosphoranes with aldehydes or ketones reaction of certain ylids with halogen compounds (scoopy reactions)... 

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