Ketone Definition
Ketone Definition A ketone is a compound containing a carbonyl functional group bridging two groups of atoms. The general formula for a ketone is RC(=O)R' where R and R' are alkyl or aryl groups. IUPAC ketone functional group names contain "oxo" or "keto". Ketones are named by changing the -e on the end of the parent alkane name to -one. Examples: Acetone is a ketone. The carbonyl group is connected to the alkane propane, therefore the IUPAC name for acetone would be propanone. Continue reading >>
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 >>
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 >>
An Inert Hydrocarbon Skeleton Onto Which Functional Groups (fgs) Are Attached Or Superimposed.
Organic Functional Groups: Aldehydes, ketones, primary alcohols, etc. (Indonesian Translation of this page) Organic chemistry is dominated by the "functional group approach", where organic molecules are deemed to be constructed from: The functional group approach "works" because the properties and reaction chemistry of a particular functional group (FG) can be remarkably independent of environment. Therefore, it is only necessary to know about the chemistry of a few generic functions in order to predict the chemical behaviour of thousands of real organic chemicals. Organic molecules are also named using the functional group approach: 2-hexanone 2-hexanol 2-chlorohexane The rule is that functions assume their distinct identity when separated by –CH2– groups. Thus, the carbonyl, C=O, and hydroxy, OH, of a carboxylic acid, RCOOH, are part of a single function and are NOT "alcohol-plus-ketone": A Couple of Words About The Functional Group Approach The functional group approach is 100% empirical in that it is determined by experiment and experience, and not by theory (unlike VSEPR, for example.) A multifunctional entity like the drug molecule morphine has several functional groups and chiral centres: Professional chemists consider large multifunctional organic molecules in terms of 'substructures' rather than functional groups. Ring systems, for example, are better considered as substructures, although the dividing line can be fuzzy... What You Need To Know To be proficient in organic chemistry at university entrance level [ie, American AP, British A-Level or French Baccalaureate] exam systems, in other words be able to: name organic molecules predict solubility in different types of solvent predict chemical reactivity predict spectra it is absolutely essential to be abl Continue reading >>
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 >>
Structural Biochemistry/organic Chemistry/organic Functional Group/carbonyl/ketone
A ketone is another functional group under the general groups of carbonyls. In a ketone, the carbonyl carbon is doubly-bonded to an oxygen, and single bonded to two alkyl groups, which can be either identical or different. It is important for both “R” groups to be alkyl groups – if the “R” group is an “H”, it becomes an aldehyde, a carboxylic acid if the “R” group is an “OH”, and an ester if the “R” group is “OR.” The carbon atom next to the carbonyl carbon is the alpha-carbon. By analogy, the hydrogen’s attached to the alpha-carbon are the alpha-hydrogens. File:O P281777.jpg IUPAC Nomenclature 1. In terms of functional group priority, ketones take priority over everything but carboxylic groups and aldehydes.If an aldehyde or carboxylic acid group is there, the ketone is no longer the highest priority and thus, becomes an oxo- prefix. 2. First count the longest carbon chain which contains the carbonyl compound. Name this chain according to normal IUPAC rules. 3. Number the chain such that the carbonyl carbon has the lowest number. 4. The oxygen is designated in the name with the number of the carbon it is on. 5. The suffix of ketones is "-one" so the "e" in the alkyl chain is replaced with "-one." Another method of naming ketones exists though this method is not used as much. In this method of nomenclature, the two alkyl groups on either side of the carbonyl group are mentioned separately. For example, look at the example of propan-2-one or 2-propanone. Another way of naming this, would be to take the carbons #2 and #3 as one group and #1 as another. The carbonyl carbon becomes a part of the longer alkyl chain - in this example, both are equivalent so it does not matter. Then each side is named and the word "ketone" put at the end of it. Continue reading >>
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 >>
Chapter 5 Aldehydes And Ketones
5.1 Introduction H Aldehydes have a -C=O functional group. An aldehyde requires that at least one of the bonds on the C=O group is a hydrogen atom. When the carbonyl group (C=O) has two C atoms bonded to it is classified as a ketone. 5.2 Naming Aldehydes and Ketones Systematic: methanal ethanal propanal butanal Common: formaldehyde acetaldehyde You should know the common names! They are more commonly used than the systematic names. Ketones: Systematic: propanone 1,3-dihydroxypropanone 3-heptanone Common: acetone dihydroxyacetone(DHA) The ketone is assigned a number on the chain starting from whichever end gives the smaller number. It takes priority over branches off the chain. Methanal (formaldehyde) is a commonly used preservative for biological specimens although concern about it being a mild carcinogen has prompted efforts to reduce its use and to provide very good ventilation when it is used to minimize exposure. Propanone (acetone) is commonly used in nail polish remover. It is also a metabolic product sometimes formed by diabetics who are not controlling their blood sugar. It is readily detected, because it makes the breath smell like nail polish remover or “fruityâ€, not a normal situation! This condition is called ketosis, indicating the presence of ketones in the blood. This condition is also commonly associated with blood acidosis and the combined condition is referred to as ketoacidosis. Dihydroxyacetone is the active ingredient in some sunless sun tanning lotions. It reacts with amino acids in the skin to form melaninoids which have a brown color. In its original formulation, it gave an orange tan but improvements in formulations have improved its esthetics considerably. It absorbs primarily in the UV-A range (320-400 nm) but only with a typical SPF Continue reading >>
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 >>
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 >>
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 >>
Ketones
Nomenclature Formula 3D structure Functional class name = alkyl alkyl ketone Substituent suffix = -one e.g. propan-2-one Substituent prefix = oxo- The root name is based on the longest chain including the carbonyl group. The chain is numbered so as to give the ketone carbonyl the lowest possible number. The ketone suffix is appended after the hydrocarbon suffix minus the "e" : e.g. -ane + -one = -anone or -ene + one = -enone etc. Functional group is a ketone, therefore suffix = -one Hydrocarbon structure is an alkane therefore -ane The longest continuous chain is C5 therefore root = pent The first point of difference rule requires numbering from the left as drawn to make the ketone group locant 2- pentan-2-one or 2-pentanone CH3CH2CH2C(=O)CH3 window1._cover(false)Jmol._Canvas2D (Jmol) "window1"[x]loading... -- required by ClazzNode Continue reading >>
Other Oxygen-containing Functional Groups
Learning Objective 1. Identify the aldehyde, ketone, acid, ester, and ether functional groups. 2. Use proper naming conventions for aldehyde, ketone, carboxylic acid, and ester- and ether-containing molecules. There are other functional groups that contain oxygen atoms. A carbonyl group is formed when an O atom and a C atom are joined by a double bond. In this diagram, the R group represents any hydrocarbon chain: If one bond of the carbonyl group is made to a hydrogen atom, then the molecule is further classified as an aldehyde. When naming aldehydes, the main chain of C atoms must include the carbon in the carbonyl group, which is numbered as position 1 in the carbon chain. The parent name of the hydrocarbon is used, but the suffix –al is appended. (Do not confuse –al with –ol, which is the suffix used for alcohols.) So we have Methanal has a common name with which you may be familiar: formaldehyde. The main thing to note about aldehydes is that the carbonyl group is at the end of a carbon chain. A carbonyl group in the middle of a carbon chain implies that both remaining bonds of the carbonyl group are made to C atoms. This type of molecule is called a ketone. Despite the fact that aldehydes and ketones have the same carbonyl group, they have different chemical and physical properties and are properly grouped as two different types of compounds. The smallest ketone has three C atoms in it. When naming a ketone, we take the name of the parent hydrocarbon and change the suffix to –one: The common name for propanone is acetone. With larger ketones, we must use a locant number to indicate the position of the carbonyl group just before the suffix, as we did with alkenes and alkynes: There is a non-IUPAC way to name ketones that is commonly used as well: name the a Continue reading >>
Reactions Of Aldehydes And Ketones
Aldehydes and ketones undergo a variety of reactions that lead to many different products. The most common reactions are nucleophilic addition reactions, which lead to the formation of alcohols, alkenes, diols, cyanohydrins (RCH(OH)C&tbond;N), and imines R 2C&dbond;NR), to mention a few representative examples. The main reactions of the carbonyl group are nucleophilic additions to the carbon‐oxygen double bond. As shown below, this addition consists of adding a nucleophile and a hydrogen across the carbon‐oxygen double bond. Due to differences in electronegativities, the carbonyl group is polarized. The carbon atom has a partial positive charge, and the oxygen atom has a partially negative charge. Aldehydes are usually more reactive toward nucleophilic substitutions than ketones because of both steric and electronic effects. In aldehydes, the relatively small hydrogen atom is attached to one side of the carbonyl group, while a larger R group is affixed to the other side. In ketones, however, R groups are attached to both sides of the carbonyl group. Thus, steric hindrance is less in aldehydes than in ketones. Electronically, aldehydes have only one R group to supply electrons toward the partially positive carbonyl carbon, while ketones have two electron‐supplying groups attached to the carbonyl carbon. The greater amount of electrons being supplied to the carbonyl carbon, the less the partial positive charge on this atom and the weaker it will become as a nucleus. The addition of water to an aldehyde results in the formation of a hydrate. The formation of a hydrate proceeds via a nucleophilic addition mechanism. 1. Water, acting as a nucleophile, is attracted to the partially positive carbon of the carbonyl group, generating an oxonium ion. Acetal formation reacti Continue reading >>
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 >>
