Ketones carbonyl groups

Two aldehydes two ketones or one aldehyde and one ketone may be formed Let s recall the classes of carbonyl compounds from Table 4 1 Aldehydes have at least one hydrogen on the carbonyl group ketones have two carbon substituents—alkyl groups for example—on the carbonyl Carboxylic acids have a hydroxyl substituent attached to the carbonyl group... 

Peroxyl radicals are known to react with olefins by an addition reaction (see Chapter 2). The same reaction was proposed for compounds with carbonyl groups (ketones, esters [77]). 

Although they are much less common, the fragmentations can also be assisted by nitrogen or sulfur substiments at the a-carbon atom. An immonium salt has to be an intermediate in the fragmentation of a-amino oximes, which on hydrolysis produce a carbonyl group (ketone or aldehyde). 

Aldehydes have at least one H bonded to the carbonyl group ketones have only R s or Ar s. ALDEHYDES... 

Alkynic Ketones. The reagent is very sensitive to the steric requirements of the carbonyl group. Ketones are reduced at considerably slower rates than aldehydes. Alkynic ketones are reduced at somewhat slower rates than aldehydes, but generally proceed at 25 °C. An alkynic ketone may be reduced in the presence of a methyl ketone (eq 3). 

Q H atom is bonded to the carbonyl group. Ketones have two carbon atoms bonded to a... 

Aldehydes and ketones contain the carbonyl group, C=0. In aldehydes, at least one H atom is bonded to the carbonyl group. Ketones have two carbon atoms bonded to a carbonyl group. Models of formaldehyde (the simplest aldehyde) and acetone (the simplest ketone) are shown in Figure 27-16. 

Formaldehyde is an exception and is nearly completely hydrated in aqueous solution. Unhindered aliphatic aldehydes are approximately 50% hydrated in water. Aryl groups disfavor hydration by conjugative stabilization of the carbonyl group. Ketones are much less extensively hydrated than aldehydes. Aldehydes and ketones with highly electronegative substituents such as trichloroacetaldehyde and hexafluoroacetone are extensively hydrated. a-Dicarbonyl compounds, such as biacetyl and ethyl pyruvate, are also significantly hydrated. Table 7.4 gives the for a number of carbonyl compounds. Data on other compounds are available in Table 3.23. 

Carbonyl group Ketones Aldehydes Carboxylic acids Carboxyl group Ester Polymer... 

The chemical reactions of ketones are similar in many ways to those of aldehydes. The carbonyl group is polarized, with positive charge on the carbon and negative charge on the oxygen. Thus nucleophilic addition can occur at the carbonyl group. Ketones thus ... 

For example, the versatility of Cp2Ti=CH2 is illustrated by the conversion of various types of carbonyl groups (ketones, esters, lactones, imides,. ..) to the corresponding methylene derivatives [103-105]. 

Both aldehydes and ketones contain a carbonyl group (/ ). Ketones have an R group attached to both sides of the carbonyl group, while aldehydes have an R group on one side of the carbonyl group and a hydrogen atom on the other. (An exception is formaldehyde, which is an aldehyde with two H atoms attached to the carbonyl group.)... 

An aldehyde contains the carbonyl group. Ketones, carboxylic acids, and esters also contain the carbonyl group. 

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