Reactions of the Carbonyl Group

Reaction of the carbonyl group of pi perl done with cyanide and aniline leads to formation of a cyanohydrin-like function known as an oc-aminonitrile (37) hydrolysis under... 

Monosaccharides normally exist as cyclic hemiacetals rather than as open-chain aldehydes or ketones. The hemiacetal linkage results from reaction of the carbonyl group with an —OH group three or four carbon atoms away. A... 

Recently a quantitative method for the determination of carbonyl groups in oxidized xylan has been developed.106 The method involves the reaction of the carbonyl group with O-methylhydroxylamine hydrochloride to form the corresponding oxime with the liberation of one mole of titratable acid. 

The reactions of the carbonyl group form the basis of many qualitative methods for the detection of carbohydrates and several have been used quantitatively. These are general methods that often only measure the total amount present in the sample. However, in some cases, reagents or reaction conditions have been modified to improve specificity. 

An analogue of amitriptyline which contains an additional double bond in the central seven membered ring shows much the same activity as the prototype. Treatment of dibenzocycloheptanone 7 with N-bromosuccinimide followed by triethyl amine serves to introduce the additional double bond by the bromination-dehydrohalogenation sequence. Reaction of the carbonyl group with the Grignard reagent from 3-chloropropyl-N,N-dimethyl amine serves to introduce the side chain (73). Acid catalyzed dehydration affords the antidepressant compound cyclobenzaprine (74). ... 

The oxidation of dihetarylethene 44 with m-chloroper-benzoic acid (m-CPBA) in CH2CI2 afforded 1,1-dioxide 67 (06T5855, 073173, 08CC4622, 09JMC97) in yields up to 90% in the case of the 6-acetyl derivative, the yield of bis-sulfone 68 was only 35% (06T5855) because of a Baeyer-ViUiger oxidation side reaction of the carbonyl group. Protection of the latter as the dioxolane derivative made it possible to increase the yield of 69 to 72% (Scheme 21). 

Formation of hydroxamic acids via the reaction of the carbonyl group of aldehydes and a-oxo acids with the aromatic or aliphatic C-nitroso group belongs to the small number of nucleophilic reactions of the C-nitroso group. ... 

Acyl substituents at the 3- and/or 4-positions result in decreased hydrolytic stability compared with the alkyl and aryl derivatives described above. Despite this constraint most of the usual reactions of the carbonyl group are possible. Aldehydes <9ILA1211> and ketones are oxidized to the carboxylic acid, borohydride reduction affords the expected alcohols, and epoxides are formed on reaction with diazomethane. Oximes and arylhydrazones are formed with hydroxylamine and arylhydrazines, and the products may subsequently undergo monocyclic rearrangement involving the oxadiazole to give the corresponding isomeric furazans and 1,2,3-triazoles (Section 4.05.5.1.4). 

Step, aldol condensation to form the benzylidene derivative (12-3). Conjugate addition of a second mole of acetoacetate would then afford the 1,5-diketone (12-4). Reaction of the carbonyl groups with ammonia will lead to the formation of the dihydropyridine ring. Alternatively, acetoacetate may go on to form the imine (12-5) reaction of this with the aldol product (13-3) will give the same dihydropyridine. The product, nifedipine (12-6) [13], has been used extensively for the treatment of angina and hypertension. 

In the acyclic derivatives, the possibility of ortho-ester formation between C-l and C-2 would be lessened by a more facile reaction of the carbonyl group with ammonia. 

CARBONYL COMPOUNDS I. ALDEHYDES AND KETONES. ADDITION REACTIONS OF THE CARBONYL GROUP... 

Carbonyl Compounds I. Aldehydes and Ketones. Addition Reactions of the Carbonyl Group halides). The naming of these compounds is described in Sections 7-4 to 7-7. 

Carbonyl Compounds I. Aldehydes and Ketones. Addition Reactions of the Carbonyl Group... 

We turn now to discuss a few specific addition reactions of the carbonyl groups of aldehydes and ketones. We shall not attempt to provide an extensive catalog of reactions, but will try to emphasize the principles involved with especially important reactions that are useful in synthesis. 

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