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What Are Ketones In Organic Chemistry?

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 >>

Ketone To Difluoro

Ketone To Difluoro

Home Ketone to Difluoro Common Conditions: DAST DAST is a nucleophilic fluorinating reagent. DAST is not as reactive towards ketones as it is with alcohols but conditions are still typically mild (0 C to RT). DAST can be unstable if heated (possible detonation at >90 C). The solvent of choice is usually DCM.[1][2][3] Examples Deoxo-Fluor Deoxo-Fluor is a nucleophilic fluorinating reagent with similar and, in some cases, superior reactivity to DAST. Deoxo-Fluor is more thermally stable than DAST.[3] Examples Reaction Map: The reaction map is intended to provide insight into possible reactions one step before and after the title reaction. It also serves as an alternative way to navigate the website, and as a means of coming up with retrosynthetic ideas. Click on the reaction arrow to visit the page. References: 1) Smith, M. B.; March's Advanced Organic Chemistry 2) Pearson, A. J.; Roush, W. R.; Handbook of Reagents for Organic Synthesis, Activating Agents and Protecting Groups 3) Singh, R. P.; Shreeve, J. M.; Synthesis 2002, No. 17, 2561-2578 Continue reading >>

The Basics Of General, Organic, And Biological Chemistry, V. 1.0

The Basics Of General, Organic, And Biological Chemistry, V. 1.0

Explain why the boiling points of aldehydes and ketones are higher than those of ethers and alkanes of similar molar masses but lower than those of comparable alcohols. Compare the solubilities in water of aldehydes and ketones of four or fewer carbon atoms with the solubilities of comparable alkanes and alcohols. Name the typical reactions take place with aldehydes and ketones. Describe some of the uses of common aldehydes and ketones. The carbon-to-oxygen double bond is quite polar, more polar than a carbon-to-oxygen single bond. The electronegative oxygen atom has a much greater attraction for the bonding electron pairs than does the carbon atom. The carbon atom has a partial positive charge, and the oxygen atom has a partial negative charge: In aldehydes and ketones, this charge separation leads to dipole-dipole interactions that are great enough to significantly affect the boiling points. Table 14.5 shows that the polar single bonds in ethers have little such effect, whereas hydrogen bonding between alcohol molecules is even stronger. Table 14.5 Boiling Points of Compounds Having Similar Molar Masses but Different Types of Intermolecular Forces Compound Family Molar Mass Type of Intermolecular Forces Boiling Point (°C) CH3CH2CH2CH3 alkane 58 dispersion only –1 CH3OCH2CH3 ether 60 weak dipole 6 CH3CH2CHO aldehyde 58 strong dipole 49 CH3CH2CH2OH alcohol 60 hydrogen bonding 97 Formaldehyde is a gas at room temperature. Acetaldehyde boils at 20°C; in an open vessel, it boils away in a warm room. Most other common aldehydes are liquids at room temperature. Although the lower members of the homologous series have pungent odors, many higher aldehydes have pleasant odors and are used in perfumes and artificial flavorings. As for the ketones, acetone has a pleasant odor 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 >>

Ketones And Aldehydes

Ketones And Aldehydes

Your chemical reactions can be run safely and effectively with US-made clamps and other laboratory accessories from Safety Emporium. According to the International Union of Pure and Applied Chemistry (IUPAC) naming (nomenclature) rules, simple ketones are named by taking the name of the longest acyclic hydrocarbon chain in the molecule, dropping the terminal "e" (if present), and adding the suffix "one". In situations where there are other functional groups that take naming precedence, the ketone may be indicated by the use of "oxo". Certain other ketone-containing substructures have additional naming rules that are beyond the scope of our current discussion: Under IUPAC nomenclature aldehydes are named by taking the name of the longest acyclic hydrocarbon chain in the molecule, dropping the terminal "e" (if present), and adding the suffix "al", "aldehyde" or "carbaldehyde". In some cases the prefix "formyl" may be used. Two aldehydes are indicated by the suffix "dial". In addition, a number of trivial (traditional) names are still recognized. For detailed naming rules see Further Reading below. Aldehydes and ketones are widely used industrial chemicals both as solvents and as chemical intermediates (ingredients for other chemicals). Most can be classified as volatile organic compounds meaning that their vapors may be easily inhaled or ignited. Many ketones and aldehydes are also flammable as liquids and solids. Training materials, handbooks, posters and videos at Safety Emporium can help your employees protect themselves from hazards such as formaldehyde. Important note: formaldehyde is an industrially important aldehyde that is used on the billion ton scale. Glutaraldehyde is a "cold sterilent" used widely in the health care industry. Both are potent sensitizers. Expo 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 >>

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 >>

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 >>

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 >>

3.3.8 Aldehydes And Ketones (a-level Only)

3.3.8 Aldehydes And Ketones (a-level Only)

Aldehydes, ketones, carboxylic acids and their derivatives all contain the carbonyl group which is attacked by nucleophiles. This section includes the addition reactions of aldehydes and ketones. Content Opportunities for skills development Aldehydes are readily oxidised to carboxylic acids. Chemical tests to distinguish between aldehydes and ketones including Fehling’s solution and Tollens’ reagent. Aldehydes can be reduced to primary alcohols, and ketones to secondary alcohols, using NaBH4 in aqueous solution. These reduction reactions are examples of nucleophilic addition. The nucleophilic addition reactions of carbonyl compounds with KCN, followed by dilute acid, to produce hydroxynitriles. Aldehydes and unsymmetrical ketones form mixtures of enantiomers when they react with KCN followed by dilute acid. The hazards of using KCN. Students should be able to: write overall equations for reduction reactions using [H] as the reductant outline the nucleophilic addition mechanism for reduction reactions with NaBH4 (the nucleophile should be shown as H–) write overall equations for the formation of hydroxynitriles using HCN outline the nucleophilic addition mechanism for the reaction with KCN followed by dilute acid explain why nucleophilic addition reactions of KCN, followed by dilute acid, can produce a mixture of enantiomers. AT b, d and k PS 2.2 Students could carry out test-tube reactions of Tollens’ reagent and Fehling’s solution to distinguish aldehydes and ketones. Continue reading >>

Journal Of The Chemical Society, Perkin Transactions 1

Journal Of The Chemical Society, Perkin Transactions 1

Electro-organic chemistry. Part 93. Electro-organic transformation of aldehydes and ketones to α-hydroxylated acetals utilizing mediators and some synthetic uses of the products Electro-oxidation of aldehydes (R1R2CHCHO) and ketones (R1R2HCOR3) in methanol containing iodide ion (I–) and KOH gave the corresponding α-hydroxylated acetals [R1R2C(OH)CH(OMe)2 and R1R2C(OH)C(OMe)2R3, respectively] in good yields. The first step of this oxidation is explained in terms of the attack of an anodically generated active iodine species ‘I+’ on enols of R1R2CHCHO and R1R2CHCOR3. α-Hydroxy acetals were useful starting materials as exemplified by reaction with aniline or methyl carbamates in the presence of Lewis acids to afford β-keto amine derivatives. The anodic oxidation of α-hydroxy acetals was also carried out. 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 >>

A Simple Formula For 7 Important Aldehyde/ketone Reactions

A Simple Formula For 7 Important Aldehyde/ketone Reactions

Here’s one thing you’re going to learn about reactions of aldehydes and ketones. There’s a LOT of repetition in the mechanism. You’ll see this in more detail soon, but let’s get a taste of how things work. Imagine you’re a guitar player. And someone tells you that you need to learn how to play 14 songs… ASAP. Sounds scary, right? But what if you then found that each of these songs had the exact same sequence of chords, and only differed in their lyrics? That’s a lot easier. We’re going to go through 14 reactions in this post. BUT… before you run away screaming… it’s really just ONE reaction… that works on both aldehydes and ketones… that has seven different variants. That sounds a lot simpler, right? All of the following reactions listed here proceed through the exact same sequence: Addition of nucleophile to the carbonyl carbon. Protonation of the oxygen. The reactions are the following: Grignard reaction Addition of organolithiums Reduction of aldehydes and ketones with NaBH4 and LiAlH4 Addition of (-)CN to give cyanohydrins This works for both aldehydes and ketones (even though just aldehydes are shown here). Apologies – big image. All we’re doing here is changing the identity of the nucleophile! It’s like having a formula, and all we’re doing is plugging a different nucleophile into the formula. Do you see how knowing the mechanisms here is going to make your life much easier? Because instead of having to keep track of 14 different reactions (7 different nucleophiles with aldehydes or ketones) you’re really just learning ONE reaction, with 7 different nucleophiles and two variants (aldehydes/ketones). Thanks for reading! James Organic Chemistry 2 builds on the concepts from Org 1 and introduces a lot of new reactions. Here is an 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 >>

Aldehydes And Ketones

Aldehydes And Ketones

Topic Review on "Aldehydes and Ketones": Background for Aldehydes and Ketones An aldehyde contains at least one hydrogen attached to the C of a C=O (carbonyl group). A ketone contains two alkyl groups attached to the C of the carbonyl group. The carbon in the carbonyl is sp2 hybridized, has a bond angle of 120o, and is trigonal planar. Aldehydes and ketones have dipole-dipole attractions between molecules, and no hydrogen bonding between molecules. These compounds can hydrogen bond with compounds have O-H or N-H bonds. The melting points and boiling points of aldehydes and ketones are between alkanes and alcohols. Small aldehydes and ketones are soluble in water. Some compounds are very flammable. Uses of Aldehydes and Ketones Formaldehyde can be used to preserve dead animals. Acetone is a common fingernail polish remover and is a solvent. Acetone is very flammable. 2-Butanone (MEK, methyl ethyl ketone) is used as a solvent and paint stripper. 2-Butanone is very flammable. Benzaldehyde is an almond extract. (-)-Carvone is used as spearmint flavoring. (+)-Carvone is used as caraway seed flavoring. Vanillin is the vanilla flavoring. IUPAC Nomenclature for Aldehydes and Ketones For the IUPAC nomenclature, the longest continuous carbon chain is the parent compound. Number the chain so that the C-O or bond has the lowest possible number. Give the location of the C-O bond with a number for ketones. From the alkyl prefixes, use [email protected] for aldehydes, and [email protected] for ketones. Name and number substituents. Common Nomenclature for Aldehydes and Ketones A ketone is named as an alkyl alkyl ketone. Use the common prefixes (n, iso, sec, tert, neo). Alphabetize the groups. Synthesis of Aldehydes and Ketones Zero degree and primary alcohols are oxidized with pyridinium chlorochromate to Continue reading >>

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