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How Are Ketones Named

Nomenclature

Nomenclature

IUPAC Names The naming of ketones is actually fairly simple, if you use the IUPAC method. It is very similar to the naming of alcohols. You start by choosing the longest carbon chain you can find that includes the carbon from the carbonyl group and use the length of that carbon chain as your base name. You change the ending by removing the -e and adding -one, and adding a number at the beginning of the name to indicate which carbon is double bonded to the oxygen. Then, if there are any side groups attached to the main chain, those are added to the front of the name with the appropriate numbers to show their location. Example A specific example is shown here (from Example 12-b in your workbook): butanone is formed from 2-butanol. The carbon chain is four carbon atoms long. Therefore, we have "butane" as a starting point. One of those carbons is double bonded to an oxygen. This make the compound a ketone. This means that we replace the -e ending on the "butane" with an -one ending to get butanone. (We could also use a 2- in front of this name to indicate that it is the 2nd carbon which is a member of the carbonyl group. This gives the name 2-butanone for this particular compound. However, the 2- is unnecessary here since if the carbonyl group were to be moved one carbon to the right we would start numbering from the right side of the compound and that carbon would be #2.) H H H | | | H-C-C-C-C-H | || | | H O H H butanone In this example I would also like to point out that the alcohol we start with, and the ketone we end up with both have the same number of carbon atoms. In addition, the carbonyl group in the ketone is in the same location as the hydroxyl group in the alcohol. This is a very important consideration when you are trying to make a particular ketone. You need 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

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 >>

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 >>

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

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

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

Aldehydes And Ketones

Aldehydes And Ketones

Aldehydes are easily oxidized and more reactive than ketones. Ketones are more difficult to oxidize and are less reactive than aldehydes. The structure of the aldehyde and ketone is a sp2 NOMENCLATURE Aldehydes: common names The common names of aldehydes end with the word aldehyde and are based on the name of the carboxylic acid they are derived from. Aldehydes: IUPAC names The IUPAC names end with -al. The aromatic names of aldehydes are often derived from the common names. If there are two names listed, the first is the common and the second is IUPAC. If only one name is listed, it serves as both the IUPAC and common. Many times it is too difficult to name an aldehyde using the common names, so it defaults to the IUPAC system. But, many times the common name system of numbering is used in which Greek letters are substituted for the numbers. The carbonyl group always gets the number one position, while the Greek letters (a,b,g,d) are used in the common names starting at the second carbon (first available carbon for a side group). Ketones: Common names The simplest ketone is called acetone. The other names of ketones list the two groups on each side of the carbonyl group followed by the word ketone. A ketone in which the carbonyl group is attached to a benzene ring is named a -phenone. The longest chain containing the carbonyl group is considered the parent structure and the -e is replaced by -one. The carbonyl group is given the lowest possible number. PHYSICAL PROPERTIES The polar carbonyl group makes ketones and aldehydes polar. As the molecular weights increase, so do their melting and boiling points. They have lower boiling points than comparable alcohols or carboxylic acids. The lower aldehydes and ketones are appreciably soluble in water and borderline solubility Continue reading >>

Ketones

Ketones

Abstract As already mentioned in Chapter 20, which deals with aldehydes, compounds containing the carbonyl group (>C=O, commonly written CO) attached to two carbon atoms are called ketones. In that chapter the close structural relationship between aldehydes and ketones is pointed out, and the need in systematic nomenclature to distinguish between these two types of carbonyl compounds is questioned. Nevertheless, since modern usage continues to reflect the desire of organic chemists to treat aldehydes and ketones as two separate functional classes and since no official approval has yet been given to proposals for a unified nomenclature, the traditional approach is retained in this book. Also included in this chapter are thioketones, which contain the thiocarbonyl group (>C=S), and quinones, which are a sub-class made up of cyclic unsaturated ketones having two carbonyl groups directly attached to a six-membered ring containing two double bonds. Structures in which an ester, amide, or anhydride 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 >>

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 >>

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 >>

14.9 Aldehydes And Ketones: Structure And Names

14.9 Aldehydes And Ketones: Structure And Names

Learning Objectives 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. Note 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. Continue reading >>

Organic Chemistry- Aldehydes And Ketones I Flashcards Preview

Organic Chemistry- Aldehydes And Ketones I Flashcards Preview

The carbonyl group First carbonyl is a component of many different functional groups (carboxylic acid, ester, amides, anhydrides) The carbonyl has the unique ability to behave as either a nucleophile (as in condensation reactions) or an electrophile (as in nucleophilic addition reactions) Continue reading >>

Ll.l Aldehydes Ond Ketones

Ll.l Aldehydes Ond Ketones

Focus l3.l Aldehydes and Ketones 595 AIM: To describe the corbon-oxygen bond of the corbonyl group of oldehydes ond ketones. The functional group known as the carbonyl group ( )C-O)-a carbon ato m and an oxy gen atonx j o ined by a double b o nd-is fciund in comp ounds called aldehydes arrd ketones. Structures of aldehydes and ketones Aldehydes are organic compounds in which the carbonyl carbon-the car- bon to which the oxygen k bonded-is always joined to at least one hydro- gen.The general formula for an aldehyde is Carbonr.l. ox'gen \ t O - ^ - L ^ - . | - - ^ . . - 1a---zCatbonvl grouP R-C-H I Carbonyl / carbon This structural formula is often abbreviated to RCHO. Ketones are organic compounds in which the carbonyl carbon is joined to two other carbons: Carbonrtl. orygen \ O - ^ * L ^ . ^ , , r ^ - ^ , . ^ !1 <-_-- CarA on1'l group R-C-R ,( Carbonyl/ carbon The abbreviated form for a ketone is RCOR. Note the similarity in structure of aldehydes and ketones. Because they both contain the carbonyl group, the chemistry of aldehydes and ketones is similar. Both aldehydes and ketones are highly reactive, but aldehydes are generally the more reactive of the two classes. Namtng aldehydes and ketones The IUPAC system may be used for naming aldehydes. We must first identify the longest hydrocarbon chain that contains the carbonyl car- bon. The -e ending of the hydrocarbon is replace dby -al to designate an aldehyde. Using the IUPAC system, we name the aldehydes methanal, ethanal, propanal, butanal, and so forth. In naming substituted aldehy- des, the longest chain is counted starting from the carbon of the alde- hyde group. The general structures of aldehydes and ketones are similar. ,94 CHAPTER 13 Aldehydes and Ketones I X A M P L E I 5 . I Naming a substituted aldehyde by t Continue reading >>

Try To Name The Following Compound Using These Conventions�

Try To Name The Following Compound Using These Conventions�

a. Ketones are named by dropping the -e ending of the parent name and adding -one. The substituent name for the O= group is oxo. Ketones can also be named by naming each of the two carbon groups as a separate word followed by a space and the word ketone. b. Ring compounds can be named by dropping the -e ending of the parent name and adding -one. c. Common names that you should know are... d. The Greek letters a, b, g, etc. are used at times to designate attached groups on the second, third and fourth, etc. carbons from the carbonyl. This nomenclature is common for many functional groups such as aldehydes, carboxylic acids and derivatives of carboxylic acids. Copyright � August 2000 by Richard C. Banks...all rights reserved. Continue reading >>

Aldehydes And Ketones

Aldehydes And Ketones

Can you resist the smell of a fresh baked cinnamon bun? There’s nothing like the smell of a fresh cinnamon roll. The taste is even better. But what causes that delicious taste? This flavoring comes from the bark of a tree (actually, several different kinds of trees). One of the major compounds responsible for the taste and odor of cinnamon is cinnamaldehyde. Cinnamon has been widely used throughout the centuries to treat a number of different disorders. In ancient times, doctors believed it could cure snakebite poisoning, freckles, and the common cold. Today there are several research studies being carried out on the health benefits of cinnamon. So, enjoy that cinnamon roll – it just might be good for you. Aldehydes and Ketones Aldehydes and ketones are two related categories of organic compounds that both contain the carbonyl group, shown below. The difference between aldehydes and ketones is the placement of the carbonyl group within the molecule. An aldehyde is an organic compound in which the carbonyl group is attached to a carbon atom at the end of a carbon chain. A ketone is an organic compound in which the carbonyl group is attached to a carbon atom within the carbon chain. The general formulas for each are shown below. For aldehydes, the R group may be a hydrogen atom or any length carbon chain. Aldehydes are named by finding the longest continuous chain that contains the carbonyl group. Change the –e at the end of the name of the alkane to –al. For ketones, R and R’ must be carbon chains, of either the same or different lengths. The steps for naming ketones, followed by two examples, are shown below. Name the parent compound by finding the longest continuous chain that contains the carbonyl group. Change the –e at the end of the name of the alkane t Continue reading >>

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