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Ketone General Formula

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 >>

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 >>

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 >>

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 >>

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 >>

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 >>

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 >>

Reaction Of Aldehydes And Ketones With Grignard Reagents

Reaction Of Aldehydes And Ketones With Grignard Reagents

This page looks at the reaction of aldehydes and ketones with Grignard reagents to produce potentially quite complicated alcohols. It is mainly a duplication of the information on these same reactions from a page on Grignard reagents in the section on properties of halogenoalkanes. Note: If you want to read more about these and other reactions of Grignard reagents you might like to follow this link. Use the BACK button on your browser if you want to return to this page. What are Grignard reagents? A Grignard reagent has a formula RMgX where X is a halogen, and R is an alkyl or aryl (based on a benzene ring) group. For the purposes of this page, we shall take R to be an alkyl group. A typical Grignard reagent might be CH3CH2MgBr. The preparation of a Grignard reagent Grignard reagents are made by adding the halogenoalkane to small bits of magnesium in a flask containing ethoxyethane (commonly called diethyl ether or just "ether"). The flask is fitted with a reflux condenser, and the mixture is warmed over a water bath for 20 - 30 minutes. Everything must be perfectly dry because Grignard reagents react with water. Warning! Ethoxyethane (ether) is very dangerous to work with. It is an anaesthetic, and is extremely inflammable. Under no circumstances should you try to carry out this reaction without properly qualified guidance. Any reactions using the Grignard reagent are carried out with the mixture produced from this reaction. You can't separate it out in any way. Reactions of Grignard reagents with aldehydes and ketones These are reactions of the carbon-oxygen double bond, and so aldehydes and ketones react in exactly the same way - all that changes are the groups that happen to be attached to the carbon-oxygen double bond. It is much easier to understand what is going Continue reading >>

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 >>

The Structure And Naming Of Aldehydes & Ketones

The Structure And Naming Of Aldehydes & Ketones

Doc Brown's GCE A Level AS A2 Chemistry Revising Advanced Level Organic Chemistry Revision Notes Part 5 CARBONYL COMPOUNDS NOMENCLATURE of ALDEHYDES and KETONES 5.1 The molecular structure and naming of ALDEHYDES and KETONES - including nomenclature of some isomers Nomenclature of aldehydes & ketones names and structures of aldehydes & ketones How to name aldehydes? How to name ketones? Nomenclature of substituted aldehydes or ketones - examples of acceptable names, displayed formula of aldehydes and ketones, graphic formula of aldehydes and ketones, molecular formula of aldehydes and ketones, skeletal formula of aldehydes and ketones, structural formula of aldehydes and ketones and homologous series of aldehydes and ketones, how to name the carbonyl group of compounds known as aldehydes and ketones Organic Chemistry Part 5 sub-index: 5.1.1 Nomenclature introduction * 5.1.2 Examples of aldehydes 5.1.3 Examples of ketones * 5.1.4 Other examples of substituted ketones 5.1.5 Oxidation sequence: alcohol ==> aldehyde/ketone ==> carboxylic acid Revision notes on the structure and naming-nomenclature of Aldehydes and Ketones 5.1.1 Introduction to Aldehyde and Ketone Nomenclature How do you name aldehydes? How do you name ketones? How do you name substituted aldehydes or ketones? Aldehydes and ketones are a group of compounds containing the carbonyl group, C=O. Aldehydes always have a hydrogen atom attached to the carbon of the carbonyl group, so the functional group is -CHO (see diagram above). The functional group is shown by using 'al' in the suffix part of the name e.g. methanal, ethanal, propanal etc. The prefix for the aldehyde name is based on the parent alkane minus the e. No number is required for the aldehyde group because the aldehyde group cannot be anything else ex Continue reading >>

> Aldehydes And Ketones

> Aldehydes And Ketones

Syllabus ref: 20.1 Aldehydes and ketones are both carbonyl compounds, that is they contain alkyl chains attached to a C=O group. The difference between them is that the aldehyde also has a hydrogen attached to the carbonyl group. This confers aldehydes with sightly different properties to ketones. Aldehydes Ketones Aldehydes Aldehydes have the general formula CxH2x+1CHO, although the first member of the homologous series is methanal, HCHO (x=0). The carbonyl group has a pair of electrons in a pi orbital between the carbon atom and the oxygen of the carbonyl group. This is a polarised system due to the high electronegativity of the oxygen atom. Oxidation This reactivity of the carbonyl group means that aldehydes can be oxidised easily to carboxylic acids. This is carried out using potassium dichromate(VI) in acidic solution under reflux (to prevent loss of the volatile aldehyde). Reduction In section section 10.33 the oxidation of alcohols to aldehydes was described: This reaction can be made to go in the reverse direction using a strong reducing agent. Suitable reducing agents are lithium aluminium hydride (lithium tetrahydroaluminate) or sodium borohydride (sodium tetrahydroborate). Lithium aluminium hydride (lithium tetrahydroaluminate) Lithium aluminium hydride, LiAlH4, is a highly reactive reducing agent that must be used in non-aqueous solutions, for example, ethoxyethane (ether). This is because it reacts vigorously with water. The reaction is carried out in two stages: 2 decomposition of the complex formed in 1 by adding aqueous acid to give the required product Sodium borohydride (sodium tetrahydroborate) Sodium borohydride, NaBH4, has an advantage over lithium aluminium hydride in that it is not decomposed by water at high pH and hence can be used in aqueous so Continue reading >>

Organic Chemistry/ketones And Aldehydes

Organic Chemistry/ketones And Aldehydes

Aldehydes () and ketones () are both carbonyl compounds. They are organic compounds in which the carbonyl carbon is connected to C or H atoms on either side. An aldehyde has one or both vacancies of the carbonyl carbon satisfied by a H atom, while a ketone has both its vacancies satisfied by carbon. 3 Preparing Aldehydes and Ketones Ketones are named by replacing the -e in the alkane name with -one. The carbon chain is numbered so that the ketone carbon, called the carbonyl group, gets the lowest number. For example, would be named 2-butanone because the root structure is butane and the ketone group is on the number two carbon. Alternatively, functional class nomenclature of ketones is also recognized by IUPAC, which is done by naming the substituents attached to the carbonyl group in alphabetical order, ending with the word ketone. The above example of 2-butanone can also be named ethyl methyl ketone using this method. If two ketone groups are on the same structure, the ending -dione would be added to the alkane name, such as heptane-2,5-dione. Aldehydes replace the -e ending of an alkane with -al for an aldehyde. Since an aldehyde is always at the carbon that is numbered one, a number designation is not needed. For example, the aldehyde of pentane would simply be pentanal. The -CH=O group of aldehydes is known as a formyl group. When a formyl group is attached to a ring, the ring name is followed by the suffix "carbaldehyde". For example, a hexane ring with a formyl group is named cyclohexanecarbaldehyde. Aldehyde and ketone polarity is characterized by the high dipole moments of their carbonyl group, which makes them rather polar molecules. They are more polar than alkenes and ethers, though because they lack hydrogen, they cannot participate in hydrogen bonding like Continue reading >>

What Is The Structural Difference Between Ketones And Ethers?

What Is The Structural Difference Between Ketones And Ethers?

Ketone Any class of organic compound characterized by the presence of a carbonyl group in which the carbon atom is covalently bounded by an oxygen atom and other two bond are attached to the Hydrocarbon radical. Ketone formula R-C(=O)-R' Ethers any class of organic compounds characterized by an oxygen atom bounded to two alkyl group. Ether formula R-O-R' Thus the main difference between Ketons and Ethers will be, in Ketons the Alkyl groups are attached to the centre carbon atom which in turn attached to a double bonded oxygen. Where as in ethers the alkyl goup is attached to the centre Oxygen atom. (As shown above) A ketone is an organic compound. It has a carboxyl group bonded to two other carbon atoms. It has a general formula of CnH2n0. Acetone, a solvent, is an excellent example of an important ketone. The structure that represents a ketone is RC(=))R'. Ether is another organic compound with an ether group an oxygen atom connected to two alkyl or aryl groups. Its general formula can be represented by R-0-R'. Ether is used as an anesthetic or as a solvent. Carbon-oxygen-carbon linkage in either has a bond angle of 104.5 degrees. There are two types of ethers--simple ethers or symmetrical and mixed ethers or asymmetrical. Continue reading >>

20.3 Aldehydes, Ketones, Carboxylic Acids, And Esters

20.3 Aldehydes, Ketones, Carboxylic Acids, And Esters

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: As text, an aldehyde group is represented as –CHO; a ketone is represented as –C(O)– or –CO–. 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 bond in carbon dioxide, the 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 the carbon atom at the positive end of the polar bond to yield an unstable intermediate that subsequently undergoes one or more structural rearrangements to form the final product (Figure 1). The importance of molecular structure in the reactivity of organic compounds is illustrated by the reactions that produce aldehydes and ketones. We can prepare a carbonyl group by oxidation of an alcohol Continue reading >>

Aldehydes And Ketones

Aldehydes And Ketones

Aldehydes and Ketones The connection between the structures of alkenes and alkanes was previously established, which noted that we can transform an alkene into an alkane by adding an H2 molecule across the C=C double bond. The driving force behind this reaction is the difference between the strengths of the bonds that must be broken and the bonds that form in the reaction. In the course of this hydrogenation reaction, a relatively strong HH bond (435 kJ/mol) and a moderately strong carbon-carbon bond (270 kJ/mol) are broken, but two strong CH bonds (439 kJ/mol) are formed. The reduction of an alkene to an alkane is therefore an exothermic reaction. What about the addition of an H2 molecule across a C=O double bond? Once again, a significant amount of energy has to be invested in this reaction to break the HH bond (435 kJ/mol) and the carbon-oxygen bond (375 kJ/mol). The overall reaction is still exothermic, however, because of the strength of the CH bond (439 kJ/mol) and the OH bond (498 kJ/mol) that are formed. The addition of hydrogen across a C=O double bond raises several important points. First, and perhaps foremost, it shows the connection between the chemistry of primary alcohols and aldehydes. But it also helps us understand the origin of the term aldehyde. If a reduction reaction in which H2 is added across a double bond is an example of a hydrogenation reaction, then an oxidation reaction in which an H2 molecule is removed to form a double bond might be called dehydrogenation. Thus, using the symbol [O] to represent an oxidizing agent, we see that the product of the oxidation of a primary alcohol is literally an "al-dehyd" or aldehyde. It is an alcohol that has been dehydrogenated. This reaction also illustrates the importance of differentiating between primar Continue reading >>

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