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Ketone Functional Group

Structural Biochemistry/organic Chemistry/organic Functional Group/carbonyl/ketone

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 >>

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 >>

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 >>

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 >>

Ketones

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 >>

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 >>

Lab Report-determining Reactions Of Aldehydes And Ketones

Lab Report-determining Reactions Of Aldehydes And Ketones

Abstract The aim of this experiment was to identify which functional groups the various chemicals and unknown substances belonged to using the different reaction tests. The main purpose was to determine the reactions of Aldehydes and Ketones. Aldehydes and Ketones are organic compounds consisting of the carbonyl functional group. Aldehydes contain their carbonyl group at the end of the carbon chain and are susceptible to oxidation while Ketones contain theirs in the middle of the carbon chain and are resistant to oxidation. Jones’s Test, Tollen’s Reagent and Iodoform Reaction were the three tests used to determine the reactions of aldehydes and ketones. The Chromic Anhydride test caused Aldehydes to turn blue, and Ketones orange. The Tollen’s Reagent test caused the oxidation of aldehydes thus forming a mirror-like image in the test tube rendering it a positive test and the Iodoform reaction produced a yellow precipitate in the test tube which concluded the presence of an aldehyde. Introduction The carbon-oxygen double bond is one of the most important functional groups, due to its ubiquity, which are involved in most important biochemistry processes. Reactivity of this group is ruled by the electron imbalance in the πorbitals of the bond between a more electronegative and a carbon atom. This carbon atom is more likely to undergo a nucleophillic attack, especially if the oxygen is protonated. If the carbonyl group has hydrogen’s in the α-position, it can tautomerise to the enol, thus, Keto tautomer can become Enol tautomer. Aldehydes and Ketones are organic compounds that consist of the carbonyl functional group, C=O. The carbonyl group that consists of one alkyl substituent and one hydrogen is the Aldehyde and those containing two alkyl substituents are calle Continue reading >>

Ketone Functional Group - Research Article From World Of Chemistry

Ketone Functional Group - Research Article From World Of Chemistry

The functional group of the ketones is -CO-. The carbon atom is double bonded to the oxygen. The groups connected to the remaining bonds are alkyl or aryl groups (not hydrogen, which would result in the formation of an aldehyde). The alkyl or aryl groups modify the behaviour of the ketone in the normal way; for example as the molecular mass increases the boiling point of the resultant ketone increases. One of the most common ketones is acetone. The functional group is prepared in one of two ways, either by partial chemical oxidation of a secondary alcohol or by dehydrogenation, with heat and a catalyst, of a secondary alcohol. Both of these processes remove the hydrogen from the hydroxyl group and allow a double bond to form between the connecting carbon and the oxygen. The majority of reactions in which the ketone functional group... 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 >>

An Inert Hydrocarbon Skeleton Onto Which Functional Groups (fgs) Are Attached Or Superimposed.

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 >>

Chapter 5 Aldehydes And Ketones

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 >>

Nomenclature Of Aldehydes & Ketones

Nomenclature Of Aldehydes & Ketones

Aldehydes and ketones contain the carbonyl group. Aldehydes are considered the most important functional group. They are often called the formyl or methanoyl group. Aldehydes derive their name from the dehydration of alcohols. Aldehydes contain the carbonyl group bonded to at least one hydrogen atom. Ketones contain the carbonyl group bonded to two carbon atoms. 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, 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. Naming Aldehydes The IUPAC system of nomenclature assigns a characteristic suffix -al to aldehydes. 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 always is given the #1 location position in numbering and it is not necessary to include it in the name. There are several simple carbonyl containing compounds which have common names which are retained by IUPAC. Also, there is a common method for naming aldehydes and ketones. For aldehydes common parent chain names, similar to those used for carboxylic acids, are used and the suffix –aldehyde is added to the end. In common names of aldehydes, carbon atoms near the carbonyl group are often designated by Greek letters. The atom adjacent to the carbonyl function is alpha, the next removed is beta and so on. If the aldehyde moiety (-CHO) is attached to a ring the suffix –carbaldehyde is added to the name of the ring. The carbon attached to this moiety will get the #1 location number in naming the ring. Aldehydes take their name Continue reading >>

Aldehydes And Ketones

Aldehydes And Ketones

Introduction We will focus more specifically on the organic compounds that incorporate carbonyl groups: aldehydes and ketones. Key Terms Aldehyde Formyl group Ketone Hydrogen bonding Hydration Hydrate Objectives Identify IUPAC names for simple aldehydes and ketones Describe the boiling point and solubility characteristics of aldehydes and ketones relative to those of alkanes and alcohols Characterize the process of nucleophilic addition to the carbonyl group The carbonyl group is shown below in the context of synthesizing alcohols. This functional group is the key component of aldehydes and ketones, which we will discuss here. Nomenclature for Aldehydes and Ketones Aldehydes and ketones are structurally similar; the only difference is that for an aldehyde, the carbonyl group has at most one substituent alkyl group, whereas the carbonyl group in a ketone has two. Several examples of aldehydes and ketones are depicted below. Aldehydes are named by replacing the -e ending of an alkane with -al (similarly to the use of -ol in alcohols). The base molecule is the longest carbon chain ending with the carbonyl group. Furthermore, the carbon atom in the carbonyl group is assumed to be carbon 1, so a number is not needed in the IUPAC name to identify the location of the doubly bonded oxygen atom. If the chain contains two carbonyl groups, one at each end, the correct suffix is -dial (used in the same manner as -diol for compounds with two hydroxyl groups). An example aldehyde is shown below with its IUPAC name. One- and two-carbon aldehydes have common names (one of which you will likely be familiar with) in addition to their systematic names. Both names are acceptable. Sometimes, the carbonyl group plus one proton (called a formyl group) must be treated separately for nomenclatu Continue reading >>

Organic Chemistry/overview Of Functional Groups

Organic Chemistry/overview Of Functional Groups

The number of known organic compounds is quite large. In fact, there are many times more organic compounds known than all the other (inorganic) compounds discovered so far, about 7 million organic compounds in total. Fortunately, organic chemicals consist of a relatively few similar parts, combined in different ways, that allow us to predict how a compound we have never seen before may react, by comparing how other molecules containing the same types of parts are known to react. These parts of organic molecules are called functional groups. The identification of functional groups and the ability to predict reactivity based on functional group properties is one of the cornerstones of organic chemistry. Functional groups are specific atoms, ions, or groups of atoms having consistent properties. A functional group makes up part of a larger molecule. For example, -OH, the hydroxyl group that characterizes alcohols, is an oxygen with a hydrogen attached. It could be found on any number of different molecules. Just as elements have distinctive properties, functional groups have characteristic chemistries. An -OH group on one molecule will tend to react similarly, although perhaps not identically, to an -OH on another molecule. Organic reactions usually take place at the functional group, so learning about the reactivities of functional groups will prepare you to understand many other things about organic chemistry. Don't assume that you can simply skim over the functional groups and move on. As you proceed through the text, the writing will be in terms of functional groups. It will be assumed that the student is familiar with most of the ones in the tables below. It's simply impossible to discuss chemistry without knowing the "lingo". It's like trying to learn French without Continue reading >>

Reactions Of Aldehydes And Ketones

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 >>

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