diabetestalk.net

Ketone Group

Ketone

Ketone

The Columbia Encyclopedia, 6th ed. Copyright The Columbia University Press ketone (kē´tōn), any of a class of organic compounds that contain the carbonyl group, C[symbol]O, and in which the carbonyl group is bonded only to carbon atoms. The general formula for a ketone is RCOR′, where R and R′ are alkyl or aryl groups. The simplest ketone, where R and R′ are methyl groups, is acetone; this is one of the most important ketones used in industry. Low-molecular-weight ketones are used chiefly as solvents. Ketones may be prepared by several methods, including the oxidation of secondary alcohols and the destructive distillation of certain salts of organic acids. Ketones are related to the aldehydes but are less active chemically. Continue reading >>

Reactions Of Aldehydes And Ketones

Reactions Of Aldehydes And Ketones

Reference: McMurry Ch 9 George et al Ch 2.6 Structure and bonding Contain a carbonyl group, C=O Aldehydes have at least one H attached to the carbonyl group, ketones have two carbon groups attached to the carbonyl group Carbon of the carbonyl group is sp2 hybridised The C=O bond is polar Aldehydes and ketones strongly absorb radiation around ~ 1700 cm-1 in the infrared region Nomenclature Aldehydes The longest chain containing the CHO group gives the stem; ending �al If substituents are present, start the numbering from the aldehyde group - C1 Ketones The longest chain containing the carbonyl group gives the stem; ending �one If substituents are present number from the end of the chain so the carbonyl group has the lowest possible number There are non-systematic names for the common aldehydes and ketones With the exception of oxidation of aldehydes, the reactions of aldehydes and ketones is dominated by nucleophilic addition. 1. Oxidation of aldehydes Aldehydes (but not ketones) may be oxidised to carboxylic acids with Cr2O72- / H+ Example: 2. Nucleophilic addition The double bond of the carbonyl group undergoes an addition reaction The polarity of the C=O bond results in the addition of a nucleophile (Nu-) to the carbon atom, breaking of the double bond and addition of H+ to the oxygen is always the second step and results in an alcohol Common nucleophiles include the Grignard reagent (RMgX), hydride ion (H- from LiAlH4 or NaBH4) In summary Examples: Grignard reaction Recap � generation of a Grignard reagent from an alkyl halide and magnesium in dry diethyl ether solvent Grignard reagents also react with carbon dioxide to generate carboxylic acids after addition of aqueous H+ Reduction Reduction of the non-polar C=C or C� C bonds in alkenes and alkynes respecti Continue reading >>

Aldehydes, Ketones, Quinones And Derivatives

Aldehydes, Ketones, Quinones And Derivatives

Quick move to entries starting with the letters C, D, H, K, Q or X. acetals:* Compounds having the structure R2C(OR')2 (R' not equal to H) and thus diethers of geminal diols. Originally, the term was confined to derivatives of aldehydes (one R = H), but now it applies equally to derivatives of ketones (neither R = H). NOC Rule C-331, GNOC Recom. R-5.6.4.1. Mixed acetals have different R' groups. See also acetonides, ketals. Cf. acylals, hemiacetals. -Hydroxy ketones, RCH(OH)C(=O)R. NOC Rule C-333. So named from the fact that they are formally derived from reductive coupling of carboxylic acyl groups. See also ketones. Compounds RC(=O)H, in which a carbonyl group is bonded to one hydrogen atom and to one R group. NOC Rule C-301.1. carbonyl compounds: 1. Compounds containing the carbonyl group, C=O. The term is commonly used in the restricted sense of aldehydes and ketones, although it actually includes carboxylic acids and derivatives. See under oxo compounds. 2. Metal carbonyls, in which carbon monoxide is a formal ligand. diosphenols: Cyclic -diketones, which exist predominantly in an enolic form. dypnones: 1,3-Diphenylbut-2-en-1-one [PhC(=O)CH=C(CH3)Ph] and its ring-substituted derivatives. Compounds having the general formula R2C(OH)OR' (R' not equal to H). NOC Rule C-331.4. GNOC Recom. R-5.6.4.2. See also lactols, hemiketals. hemiketals:* Hemiacetals having the structure R2C(OH)OR (R not equal to H), derived from ketones by formal addition of an alcohol to the carbonyl group. This term, once abandoned (NOC Rule C-331.4, footnote) has been reinstated as a subclass of hemiacetals. GNOC Recom. R-5.6.4.2. Acetals derived from ketones by replacement of the oxo group by two hydrocarbyloxy groups: R2C(OR)2 (R not equal to H). This term, once abandoned (NOC Rule C-333.1), h Continue reading >>

Functional Group Names, Properties, And Reactions

Functional Group Names, Properties, And Reactions

Functional Groups Functional groups refer to specific atoms bonded in a certain arrangement that give a compound certain physical and chemical properties. Learning Objectives Define the term “functional group” as it applies to organic molecules Key Takeaways Functional groups are often used to “functionalize” a compound, affording it different physical and chemical properties than it would have in its original form. Functional groups will undergo the same type of reactions regardless of the compound of which they are a part; however, the presence of certain functional groups within close proximity can limit reactivity. Functional groups can be used to distinguish similar compounds from each other. functional group: A specific grouping of elements that is characteristic of a class of compounds, and determines some properties and reactions of that class. functionalization: Addition of specific functional groups to afford the compound new, desirable properties. The Role of Functional Groups In organic chemistry, a functional group is a specific group of atoms or bonds within a compound that is responsible for the characteristic chemical reactions of that compound. The same functional group will behave in a similar fashion, by undergoing similar reactions, regardless of the compound of which it is a part. Functional groups also play an important part in organic compound nomenclature; combining the names of the functional groups with the names of the parent alkanes provides a way to distinguish compounds. The atoms of a functional group are linked together and to the rest of the compound by covalent bonds. The first carbon atom that attaches to the functional group is referred to as the alpha carbon; the second, the beta carbon; the third, the gamma carbon, etc. Simi Continue reading >>

Ketone Group

Ketone Group

Also found in: Thesaurus, Medical, Wikipedia. Related to ketone group: aldehyde group, alcohol group, Amide group ketone group n (Chemistry) chem the functional group of ketones: a carbonyl group attached to the carbon atoms of two other organic groups Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014 Want to thank TFD for its existence? Tell a friend about us, add a link to this page, or visit the webmaster's page for free fun content. Link to this page: Continue reading >>

Ketone

Ketone

Ketone, any of a class of organic compounds characterized by the presence of a carbonyl group in which the carbon atom is covalently bonded to an oxygen atom. The remaining two bonds are to other carbon atoms or hydrocarbon radicals (R): Ketone compounds have important physiological properties. They are found in several sugars and in compounds for medicinal use, including natural and synthetic steroid hormones. Molecules of the anti-inflammatory agent cortisone contain three ketone groups. Only a small number of ketones are manufactured on a large scale in industry. They can be synthesized by a wide variety of methods, and because of their ease of preparation, relative stability, and high reactivity, they are nearly ideal chemical intermediates. Many complex organic compounds are synthesized using ketones as building blocks. They are most widely used as solvents, especially in industries manufacturing explosives, lacquers, paints, and textiles. Ketones are also used in tanning, as preservatives, and in hydraulic fluids. The most important ketone is acetone (CH3COCH3), a liquid with a sweetish odour. Acetone is one of the few organic compounds that is infinitely soluble in water (i.e., soluble in all proportions); it also dissolves many organic compounds. For this reason—and because of its low boiling point (56 °C [132.8 °F]), which makes it easy to remove by evaporation when no longer wanted—it is one of the most important industrial solvents, being used in such products as paints, varnishes, resins, coatings, and nail-polish removers. The International Union of Pure and Applied Chemistry (IUPAC) name of a ketone is derived by selecting as the parent the longest chain of carbon atoms that contains the carbonyl group. The parent chain is numbered from the end that Continue reading >>

What Is Ketone? - Definition, Structure, Formation & Formula

What Is Ketone? - Definition, Structure, Formation & Formula

Background of Ketone Did you know that our friend aldehyde has a very close relative named ketone? By definition, a ketone is an organic compound that contains a carbonyl functional group. So you may be wondering if aldehydes and ketones are relatives, what makes them different? Well, I am glad you asked because all you have to remember is this little guy: hydrogen. While aldehyde contains a hydrogen atom connected to its carbonyl group, ketone does not have a hydrogen atom attached. There are a few ways to know you are encountering a ketone. The first is by looking at the ending of the chemical word. If the suffix ending of the chemical name is '-one,' then you can be sure there is a ketone present in that compound. Want to know another way to tell if a ketone is lurking around the corner? By its physical property. Ketones have high boiling points and love water (high water solubility). Let's dig a little deeper with the physical property of a ketone. The oxygen in a ketone absolutely loves to take all the electrons it can get its hands on. But, by being an electron-hogger, oxygen's refusal to share creates a sticky situation where some atoms on the ketone have more or less charge than others. In chemistry, an electron-hogging atom is referred to as being electronegative. An electronegative atom is more attractive to other compounds. This attractiveness, called polarity, is what contributes to ketones' physical properties. Structure & Formula Ketones have a very distinct look to them; you can't miss it if you see them. As shown in Diagram 1, there are two R groups attached to the carbonyl group (C=O). Those R groups can be any type of compound that contains a carbon molecule. An example of how the R group determines ketone type is illustrated in this diagram here. The Continue reading >>

Introducing Aldehydes And Ketones

Introducing Aldehydes And Ketones

This page explains what aldehydes and ketones are, and looks at the way their bonding affects their reactivity. It also considers their simple physical properties such as solubility and boiling points. Details of the chemical reactions of aldehydes and ketones are described on separate pages. What are aldehydes and ketones? Aldehydes and ketones as carbonyl compounds Aldehydes and ketones are simple compounds which contain a carbonyl group - a carbon-oxygen double bond. They are simple in the sense that they don't have other reactive groups like -OH or -Cl attached directly to the carbon atom in the carbonyl group - as you might find, for example, in carboxylic acids containing -COOH. Examples of aldehydes In aldehydes, the carbonyl group has a hydrogen atom attached to it together with either a second hydrogen atom or, more commonly, a hydrocarbon group which might be an alkyl group or one containing a benzene ring. For the purposes of this section, we shall ignore those containing benzene rings. Note: There is no very significant reason for this. It is just that if you are fairly new to organic chemistry you might not have come across any compounds with benzene rings in them yet. I'm just trying to avoid adding to your confusion! Notice that these all have exactly the same end to the molecule. All that differs is the complexity of the other group attached. When you are writing formulae for these, the aldehyde group (the carbonyl group with the hydrogen atom attached) is always written as -CHO - never as COH. That could easily be confused with an alcohol. Ethanal, for example, is written as CH3CHO; methanal as HCHO. The name counts the total number of carbon atoms in the longest chain - including the one in the carbonyl group. If you have side groups attached to the ch Continue reading >>

Ketone

Ketone

Previous (Kermit Roosevelt, Jr.) Next (Key (music)) A ketone (pronounced as key tone) is either the functional group characterized by a carbonyl group (O=C) linked to two other carbon atoms or a chemical compound that contains this functional group. A ketone can be generally represented by the formula: A carbonyl carbon bonded to two carbon atoms distinguishes ketones from carboxylic acids, aldehydes, esters, amides, and other oxygen-containing compounds. The double-bond of the carbonyl group distinguishes ketones from alcohols and ethers. The simplest ketone is acetone (also called propanone). Mold Test Kits Easy to Use, Fast Results Available Interpretive Lab Report moldtesting.com The carbon atom adjacent to a carbonyl group is called the α-carbon. Hydrogens attached to this carbon are called α-hydrogens. In the presence of an acid catalyst the ketone is subjected to so-called keto-enol tautomerism. The reaction with a strong base gives the corresponding enolate. A diketone is a compound containing two ketone groups. Nomenclature In general, ketones are named using IUPAC nomenclature by changing the suffix -e of the parent alkane to -one. For common ketones, some traditional names such as acetone and benzophenone predominate, and these are considered retained IUPAC names,[1] although some introductory chemistry texts use names such as propanone. Oxo is the formal IUPAC nomenclature for a ketone functional group. However, other prefixes are also used by various books and journals. For some common chemicals (mainly in biochemistry), keto or oxy is the term used to describe the ketone (also known as alkanone) functional group. Oxo also refers to a single oxygen atom coordinated to a transition metal (a metal oxo). Physical properties A carbonyl group is polar. This ma Continue reading >>

Aldehydes, Ketones, Carboxylic Acids, And Esters

Aldehydes, Ketones, Carboxylic Acids, And Esters

Learning Objectives By the end of this section, you will be able to: Describe the structure and properties of aldehydes, ketones, carboxylic acids and esters Another class of organic molecules contains a carbon atom connected to an oxygen atom by a double bond, commonly called a carbonyl group. The trigonal planar carbon in the carbonyl group can attach to two other substituents leading to several subfamilies (aldehydes, ketones, carboxylic acids and esters) described in this section. Aldehydes and Ketones Both aldehydes and ketones contain a carbonyl group, a functional group with a carbon-oxygen double bond. The names for aldehyde and ketone compounds are derived using similar nomenclature rules as for alkanes and alcohols, and include the class-identifying suffixes –al and –one, respectively: In an aldehyde, the carbonyl group is bonded to at least one hydrogen atom. In a ketone, the carbonyl group is bonded to two carbon atoms: In both aldehydes and ketones, the geometry around the carbon atom in the carbonyl group is trigonal planar; the carbon atom exhibits sp2 hybridization. Two of the sp2 orbitals on the carbon atom in the carbonyl group are used to form σ bonds to the other carbon or hydrogen atoms in a molecule. The remaining sp2 hybrid orbital forms a σ bond to the oxygen atom. The unhybridized p orbital on the carbon atom in the carbonyl group overlaps a p orbital on the oxygen atom to form the π bond in the double bond. Like the C=O bond in carbon dioxide, the C=O bond of a carbonyl group is polar (recall that oxygen is significantly more electronegative than carbon, and the shared electrons are pulled toward the oxygen atom and away from the carbon atom). Many of the reactions of aldehydes and ketones start with the reaction between a Lewis base and Continue reading >>

14.9: Aldehydes And Ketones: Structure And Names

14.9: Aldehydes And Ketones: Structure And Names

Identify the general structure for an aldehyde and a ketone. Use common names to name aldehydes and ketones. Use the IUPAC system to name aldehydes and ketones. The next functional group we consider, the carbonyl group, has a carbon-to-oxygen double bond. Carbonyl groups define two related families of organic compounds: the aldehydes and the ketones. The carbonyl group is ubiquitous in biological compounds. It is found in carbohydrates, fats, proteins, nucleic acids, hormones, and vitamins—organic compounds critical to living systems. In a ketone, two carbon groups are attached to the carbonyl carbon atom. The following general formulas, in which R represents an alkyl group and Ar stands for an aryl group, represent ketones. In an aldehyde, at least one of the attached groups must be a hydrogen atom. The following compounds are aldehydes: In condensed formulas, we use CHO to identify an aldehyde rather than COH, which might be confused with an alcohol. This follows the general rule that in condensed structural formulas H comes after the atom it is attached to (usually C, N, or O). The carbon-to-oxygen double bond is not shown but understood to be present. Because they contain the same functional group, aldehydes and ketones share many common properties, but they still differ enough to warrant their classification into two families. Here are some simple IUPAC rules for naming aldehydes and ketones: The stem names of aldehydes and ketones are derived from those of the parent alkanes, defined by the longest continuous chain (LCC) of carbon atoms that contains the functional group. For an aldehyde, drop the -e from the alkane name and add the ending -al. Methanal is the IUPAC name for formaldehyde, and ethanal is the name for acetaldehyde. For a ketone, drop the -e from t Continue reading >>

Naming Ketones

Naming Ketones

Ketones are organic chemical compounds that include a -carbonyl group (i.e. an oxygen atom attached to a carbon atom by a double covalent bond) such that the carbon atom to which the -carbonyl group is attached is itself attached to two other carbon atoms - as opposed to one other carbon atom and one hydrogen atom, which the case for aldehydes That is, ketones are a class or category of organic chemical compounds that include a carbon atom attached to both an oxygen atom (by a double covalent bond), and also to two other carbon atoms (by a single covalent bond in each case). Bearing in mind that carbon atoms form a total of 4 single covalent bonds - or equivalent in combinations of double or triple bonds, a carbon atom attached to both an oxygen atom (by a double covalent bond) and also to two other carbon atoms (by a single covalent bond in each case) cannot be the first- or last - (which are equivalent positions) carbon atom in the chain of carbon atoms that form the organic molecule of which it is a part. This position of the -carbonyl group (oxygen atom) attached to a carbon atom that is not the last carbon atom in a carbon-chain is important because it distinguishes ketones from a similar category of organic compounds, called aldehydes. In contrast to ketones, aldehydes include a -carbonyl group attached to the end-carbon in a carbon-chain. Ketone molecules can vary in size up to very long molecules most of which consist of carbon atoms attached to each other and also to hydrogen atoms. Continue reading >>

1. Nomenclature Of Aldehydes And Ketones

1. Nomenclature Of Aldehydes And Ketones

Aldehydes and ketones are organic compounds which incorporate a carbonyl functional group, C=O. The carbon atom of this group has two remaining bonds that may be occupied by hydrogen or alkyl or aryl substituents. If at least one of these substituents is hydrogen, the compound is an aldehyde. If neither is hydrogen, the compound is a ketone. The IUPAC system of nomenclature assigns a characteristic suffix to these classes, al to aldehydes and one to ketones. For example, H2C=O is methanal, more commonly called formaldehyde. Since an aldehyde carbonyl group must always lie at the end of a carbon chain, it is by default position #1, and therefore defines the numbering direction. A ketone carbonyl function may be located anywhere within a chain or ring, and its position is given by a locator number. Chain numbering normally starts from the end nearest the carbonyl group. In cyclic ketones the carbonyl group is assigned position #1, and this number is not cited in the name, unless more than one carbonyl group is present. If you are uncertain about the IUPAC rules for nomenclature you should review them now. Examples of IUPAC names are provided (in blue) in the following diagram. Common names are in red, and derived names in black. In common names carbon atoms near the carbonyl group are often designated by Greek letters. The atom adjacent to the function is alpha, the next removed is beta and so on. Since ketones have two sets of neighboring atoms, one set is labeled α, β etc., and the other α', β' etc. Very simple ketones, such as propanone and phenylethanone (first two examples in the right column), do not require a locator number, since there is only one possible site for a ketone carbonyl function. Likewise, locator numbers are omitted for the simple dialdehyde at t Continue reading >>

Protecting Groups In Grignard Reactions

Protecting Groups In Grignard Reactions

Now that we’ve gone over the most useful reactions of Grignard reagents – addition to epoxides, aldehydes, ketones, and esters – let’s go back to the topic of how to make Grignard reagents, albeit with a twist. Here’s the summary for today’s post: Introducing Yet Another Way To Royally Screw Up Making A Grignard Reagent In a previous post we said that there are cases where making Grignard reagents can fail due to the presence of an acidic proton. Like this example. The problem here is that Grignard reagents are strong bases, and will react with even weak acids (like alcohols). If we try to make a Grignard on a molecule with an acidic functional group, we’ll end up destroying our Grignard instead. We saw that one way around this problem was to protect alcohols as some kind of inert functional group (like an ether) which doesn’t react with our Grignard. Similarly, there are other cases of molecules where making a Grignard reagent will fail for similar reasons. For example: why does this reaction not give the desired Grignard reagent? The problem here, as you might have guessed if you read the last post, is that this Grignard reagent reacts with itself!!! Once formed, the Grignard would react with the ketone from the starting material. This could then react with Mg to give a new Grignard, which would react with more ketone… and so on. The result is a mess. “Protecting Groups” Mask A Functional Group From Attack If we were able to find some way to “mask” the ketone in this case, possibly as some unreactive functional group that is completely inert to Grignard reagents, then we could then make the Grignard reagent without causing any problems of self-reactivity. Then, once we’re done, we could then “unmask” the protecting or masking group, rev Continue reading >>

Ketone

Ketone

Not to be confused with ketone bodies. Ketone group Acetone In chemistry, a ketone (alkanone) /ˈkiːtoʊn/ is an organic compound with the structure RC(=O)R', where R and R' can be a variety of carbon-containing substituents. Ketones and aldehydes are simple compounds that contain a carbonyl group (a carbon-oxygen double bond). They are considered "simple" because they do not have reactive groups like −OH or −Cl attached directly to the carbon atom in the carbonyl group, as in carboxylic acids containing −COOH.[1] Many ketones are known and many are of great importance in industry and in biology. Examples include many sugars (ketoses) and the industrial solvent acetone, which is the smallest ketone. Nomenclature and etymology[edit] The word ketone is derived from Aketon, an old German word for acetone.[2][3] According to the rules of IUPAC nomenclature, ketones are named by changing the suffix -ane of the parent alkane to -anone. The position of the carbonyl group is usually denoted by a number. For the most important ketones, however, traditional nonsystematic names are still generally used, for example acetone and benzophenone. These nonsystematic names are considered retained IUPAC names,[4] although some introductory chemistry textbooks use systematic names such as "2-propanone" or "propan-2-one" for the simplest ketone (CH3−CO−CH3) instead of "acetone". The common names of ketones are obtained by writing separately the names of the two alkyl groups attached to the carbonyl group, followed by "ketone" as a separate word. The names of the alkyl groups are written alphabetically. When the two alkyl groups are the same, the prefix di- is added before the name of alkyl group. The positions of other groups are indicated by Greek letters, the α-carbon being th Continue reading >>

More in ketosis