Ketones carboxylic acid anhydrides

Phosgene is reported to combine with a wide range of oxygenated materials, including alcohols, ethers, ketones, carboxylic acids, anhydrides, lactones, esters, carbonic acid derivatives, etc. Only the reactions of COCIF with alcohols, phenols and cyclic ethers have been reported, resulting usually in the generation of fluoroformates. Such materials can often be usefully converted into the corresponding fluoro compound by means of decarboxylation in the presence of BF3, EtjO, pyridine, or other materials. 

Many compounds contain more than one functional group Prostaglandin Ei a hormone that regulates the relaxation of smooth muscles con tains two different kinds of carbonyl groups Classify each one (aldehyde ketone carboxylic acid ester amide acyl chloride or acid anhydride) Identify the most acidic proton in prostaglandin Ei and use Table 1 7 to estimate its pK ... 

One of the most systematic investigations into the use of organic chemical microscopy was made by Dunbar and his associates, who used a series of specific reagents to develop specific tests for various functional groups. Methods were developed for amines [24,25], carboxylic acids, anhydrides, and acid chlorides [26,27], aldehydes and ketones [28], hydroxy compounds [29], amino acids [30], and cations [31]. 

Carboxylic acids, anhydrides, aromatic and aliphatic hydrocarbons, alcohols, aldehydes, ketones, esters, and chlorinated solvents have only a slight effect. 

Acid anhydride Arene Ketone Carboxylic acid... 

Know the meaning of chromic anhydride, PCC, aldehyde, ketone, carboxylic acid, glycol, glycerol, sorbitol, glyceryl trinitrate (nitroglycerine), quinone, antioxidant. 

Functional groups containing n-bonds are more reactive because ir-bond is weaker and can be easily broken, e.g. aromatic rings, alkenes, alkynes, aldehydes and ketones, carboxylic acids, esters, amides, acid chlorides, acid anhydrides, nitriles, etc. 

Fig. (a) Aldehyde or alkanal (b) ketone or alkanone (c) carboxylic acid (d) carboxylic acid chloride (e) carboxylic acid anhydride (f) ester (g) amide (h) phenol. 

Food, flavors consist of numerous compounds, none of which alone is characteristic of specific food. Classes of compounds which emcompass food flavors are - hydrocarbons (aliphatic, ali-cyclic, aromatic) carbonyls (aldehydes, ketones) carboxylic acids, esters, imides, anhydrides alcohols, phenols, ethers alkylamines, alkylimines aliphatic sulfur compounds (thiols, mono-, di- and tri-sulfides) nitrogen heterocyclics (pyrroles, pyrazines, pyridines) sulfur heterocylics (thiophenes, thiazoles, trithiolane, thialidine) and oxygen-heterocyclics (lactone, pyrone, furan). Discussion will be limited to striking developments in heterocyclics. 

With Ketones, Nitromethane, Dimethyl Sulfite or Carboxylic Acid Anhydrides... 

The azolides are able to participate in a wide variety of nucleophilic olysis reactions which form aldehydes, ketones, carboxylic acids, esters, amides, thiol esters, hydrazides and anhydrides (Scheme 143). In addition, 1-trifluoroacetylimidazole (252) is a convenient reagent for the conversion of aldoximes into nitriles (Scheme 144) (81601579). 

The most important method for the preparation of aryl ketones is known as Friedel-Crafts acylation. The reaction is of wide scope. Reagents other than acyl halides can be used," including carboxylic acids," anhydrides, and ketenes. Oxalyl chloride has been used to give diaryl 1,2-diketones." Carboxylic esters usually give alkylation as the predominant product (see 11-11)." A-Carbamoyl p-lactams reacted with naphthalene in the presence of trifluoromethanesulfonic acid to give the keto-amide." ... 

Note The frequencies given for the C=0 stretching vibrations for anhydrides, acid chlorides, esters, lactones, aldehydes, ketones, carboxylic acids and amides refer to the open chain or unstrained functional group in a nonconjugated system. If the carbonyl group is conjugated with a double bond or an aromatic ring, the frequency is 30 cm less. If it is... 

Thiol carboxylic esters (1) are the most common compounds among the three types of thioester. They are activated derivatives of carboxylic acids and exhibit acylating properties similar to those of carboxylic acid anhydrides. They have therefore found widespread application in synthetic chemistry and have been used for preparing esters, amides and peptides, especially macrocyclic ketones and lactones. Several review articles concerning the chemistry of thiol carboxylic esters - - and thiol lactones have appeared. 

It should finally be pointed out that trimethylsilyl ethers can also be transformed directly into other functionalities. Oxidation with NBS leads to ketones and aldehydes, treatment with LiAllWAlCb results in deoxygenation of the alcohol, reaction with carboxylic acid anhydrides in the presence of BF3-OEt2 produces esters and on treatment with PhsP Brj acid bromides are foimed directly from TMS esters. ss... 

Other possibility for a traceless release of combinatorial compounds from solid supports. As only the desired products are cleaved during fhe reaction, these are obtained in high purity. The method is compatible wifh a whole variety of different functionalities, such as carboxylic acids, carboxylic acid anhydrides, amides, aldehydes, ketones, alcohols, and sulfonamides. 

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