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How Do You Name A Ketone As A Substituent?

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 >>

Ketones Rule C-313

Ketones Rule C-313

Aldehydes, Ketones, and their Derivatives 313.1 - The name of a ketone having a ring or rings attached to a chain which contains the carbonyl group or groups is formed from the name of the corresponding acyclic hydrocarbon, with the radical name of the ring system as a substituent, the ketone group or groups being indicated by a suffix "-one", "-dione", etc. Examples to Rule C-313.1 313.2 - Acyclic monoacyl derivatives of cyclic compounds are named (a) by the method of Rule C-313.1, (b) by the radicofunctional method of Rule C-312.2, (c) by prefixing the name of the acyl group to the name of the cyclic component, or (d) if the cyclic component is benzene or naphthalene by changing the ending "-ie acid" or "-oie acid" of the name of the acid corresponding to the acyl group to "-ophenone" or "-onaphthone", respectively. Examples to Rule C-313.2 Exceptions: The following are examples of trivial names retained for ketones: 313.3 - When a carbonyl group is attached directly to carbon atoms in two ring systems, the compound is named by the radicofunctional method provided that no other substituent is present having priority for citation as principal group (compare Rule C-316.2). Examples to Rule C-313.3 Exception: 313.4 - The name of a polyketone in which two or more contiguous carbonyl groups have rings attached at each end is formed (a) by the radicofunctional method with the functional class name "diketone", "triketone", etc., or (b) by substitutive nomenclature with "-one" suffixes. Examples to Rule C-313.4 Exceptions: See Recommendations'93 R-5.6.2 This HTML reproduction of Sections A, B and C of IUPAC "Blue Book" is as close as possible to the published version [see Nomenclature of Organic Chemistry, Sections A, B, C, D, E, F, and H, Pergamon Press, Oxford, 1979. Copyri Continue reading >>

Nomenclature Of Aldehydes And Ketones

Nomenclature Of Aldehydes And Ketones

Nomenclature of Aldehydes and Ketones The chemistry of aldehydes and ketones is influenced by the presence of carbonyl group in them. In aldehydes the carbonyl group is attached to a carbon and hydrogen, whereas in ketones it is bonded to two carbon atoms. In other words, the two remaining bonds of the carbon atom in carbonyl group are taken by hydrogen, alkyl or aryl substituents. If one of the substituent is hydrogen then the compound is called aldehyde and if none of them is hydrogen then it is a ketone. According to the IUPAC system of nomenclature -al is attached as a suffix to parent alkane for the naming of aldehydes. For example, H2C=O is named as per the IUPAC system as methanal, commonly known as formaldehyde. The aldehyde group is always attached at the end of the main carbon chain, and hence the 1st position in the numbering is always assigned to it. It is not always necessary to include numbering in the naming. Instead of IUPAC name aldehydes and ketones are also called by their common names. For aldehydes and ketones the names are reflected in Greek and Latin term. Greek letters such as α, β etc. are used for the location of the substituents in the carbon chain. The α-carbon is directly attached to the aldehyde group, β-carbon is attached to the carbon adjacent to the aldehyde group and so on. Now let’s discuss about the naming of ketones, according to IUPAC guidelines, suffix –one is assigned for the ketones. The carbonyl group can be located anywhere within the main chain and the position is decided by the location number. The numbering of the chain usually starts from the end such that the carbonyl carbon gets the lowest number. But there are some ketones such as propanone and phenylethanone which do not require any number locator as there is on 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 >>

Organic Chemistry/ketones And Aldehydes

Organic Chemistry/ketones And Aldehydes

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

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 >>

Table Of Functional Group Priorities For Nomenclature

Table Of Functional Group Priorities For Nomenclature

Here’s a little nomenclature dilemma. Let’s say you’re trying to name a molecule. You’re familiar with the familiar naming suffixes like -ol, -ene, -ane, -oic acid and so on. But then you come across a molecule which has multiple functional groups. What do you do? What suffix do you give the molecule? We need some kind of priority system for nomenclature. And so, IUPAC has developed one. If you have a molecule with, say, a carboxylic acid and a ketone you consult the table. The functional group with the highest priority will be the one which gives its suffix to the name of the molecule. So in example #1 above, the suffix of the molecule will be “-oic acid” , not “-one”, because carboxylic acids are given higher priority. However, if a ketone is present with an alcohol (example 3) then we will use the suffix, “-one” because ketones have a higher priority for nomenclature than alcohols. [You might ask: what is this based on? It’s an arbitrary agreement by IUPAC [source], although note that there is some correlation between the oxidation state of the carbon and the priority (more oxidized groups tend to be higher priority). However this really is an example of something you have to either look up , memorize, or have a computer do for you. It’s not conceptual. ] Here it is: Table of Functional Group Priorities For Nomenclature Here are some examples of applying the order of functional group priorities to solve nomenclature problems. The highest ranked functional group becomes the suffix – it’s highlighted in red. This covers most of the functional groups you’ll meet in Org1/Org2, if you run into a thioketone or some other bizarre entity, you’ll probably want to see Reusch or Wikipedia. Organic Chemistry 2 builds on the concepts from Org 1 and Continue reading >>

Iupac System And Iupac Rules Of Naming Aldehydes & Ketones

Iupac System And Iupac Rules Of Naming Aldehydes & Ketones

The IUPAC names of open chain aliphatic aldehydes and ketones are derived from the names of the corresponding alkanes by replacing the ending -e with -al and -one respectively. a) The longest carbon chain containing the carbonyl carbon is taken to decide the name of the parent alkane. b) The carbon chain is numbered from the end nearer to the carbonyl group and the substituents are prefixed in alphabetical order along with Arabic numerals including their positions in the carbon chain. The carbon of the aldehydic group and the carbonyl carbon in cyclic ketones always get the number 1. c) When the aldehyde group is attached to a ring, the numbering of the ring carbon atoms starts from the carbon atom attached to the aldehyde group. The suffix carbaldehyde is added after the full name of the hydrocarbon. The simplest aromatic aldehyde carrying the aldehyde group on a benzene ring is benzaldehyde. Other ring substituted aromatic aldehydes are derivatives of benzaldehyde is ortho-hydroxy benzaldehyde. The trivial names of aldehydes are derived from the trivial names of the corresponding carboxylic acids by replacing the ending ic, for acid with aldehyde. The positions of the substituents in the carbon chain are indicated by Greek letters a, b, g, d etc, the a-carbon being the one directly linked to the aldehyde group, theb-carbon the next and on. The common names of ketones are derived by adding the names of the alkyl or aryl groups directly linked to the carbonyl group before the word ketone. The simplest ketone is acetone. The positions of the substituents are indicated by the Greek letters a, a', b', b' and so on. a, a' carbons being the ones directly attached to the carbonyl group. Ketones with a carbonyl group attached to a benzene ring are named as phenones in the IUPA Continue reading >>

Organic Nomenclature

Organic Nomenclature

This document contains a highly compressed, simplified version of the naming rules put out by the International Union on Pure and Applied Chemistry (IUPAC). That's right, I said simplified. The actual rules must cover perfectly accurately all 20 million or so compounds discovered to date, and all 10 million or so that we will discover over the next decade or so. They are mind-bogglingly complex (to steal a phrase from Douglas Adams). The rules here are intended to work well on simple compounds, and to give the introductory student a flavor for how the system works. The naming of a compound follows several basic steps: Identify the functional groups present and assign them priority. Identify the highest priority substituent. Identify a parent portion of the molecule; name and number it. Identify the substituents and locate them on the numbered parent Assemble the name in proper order, and with proper punctuation, etc. Identify Functional Groups and Assign Priority The first step is to identify the functional groups present in the molecule. The following table has a large number of functional groups ranked in priority order. You should know that the highest priority group in your compound (towards the top of the table) is treated differently from the rest of the functional groups in the molecule. Note that some functional groups appear to have two or more carbon-containing groups; be sure you pay attention to which side of the functional group is the "main" side and which is the secondary side. For example, the "main" part of the ester group as shown below contains the R group; the secondary side contains the R' group. The main part of the functional group will be included in the parent. Carboxylic acid -oic acid* propanoic acid propionic acid Salt of acid -oate* sodium e Continue reading >>

Naming Aldehydes

Naming Aldehydes

In the IUPAC system we use the -al ending. The end e is replaced by al. So the common names of the first four aldehydes become: Now this is all pretty simple, but what if there are side chains off the main aldehyde chain. For example, take the molecule pictured on the right. Step 1 The aldehyde forms the root name Step 2 Number the carbons so that the C=O is carbon number 1. Step 3 Name all the substituents in alphabetical order. 3-methylbutanal Consider the example shown on the right. It has two substituent groups, the methyl and hydroxy. The IUPAC name is 4-hydroxy-3-methylbutanal. When naming a ketone we remove the end "e" from the name and replace it with a "one". For example propane becomes propanone. Since the carbonyl group can be located anywhere in the carbon chain a locator number is needed. . With simple molecules, such as propanone, shown on the right, a number is not needed as there can be only one location for the carbonyl group. Now lets look at he steps to derive a IUPAC name. Step 1) Identify the longest carbon chain that contains the carbonyl group and number the carbons so that the carbonyl group is on the lowest carbon. Step 2) Identify the various substituent groups Step 3) Place the substituent groups in the name in alphabetical order and use position numbers to locate the substituent groups and the carbonyl group. Step 4) Change the end e to a one. Lets take the molecule shown on the right as an example. Step 1 The longest carbon chain is pentane Step 2 No substituent groups Step 3 and 4 The carbonyl group is found at carbon number 2 . Hence the name is 2-pentanone What is the IUPAC name of this molecule? Solution What is the IUPAC name of this molecule? Solution What is the IUPAC name of this molecule? Solution Continue reading >>

Naming Of Organic Compounds

Naming Of Organic Compounds

Nomenclature rules for different groups of organic compounds and functional groups, together with examples of use of the rules There are millions of different organic compounds and it is obvious that a systematic way of naming them is necessary. This article gives definitions of the different classes of organic compounds and rules for their naming together with many examples of use of the naming rules. See also naming of inorganic binary compounds. Content (links directly to the compound classes) Acyl halides Ethers Alcohols Functional groups priority Aldehydes General naming principles Alkanes Greek numbers used as prefixes Alkenes Haloalkanes (alkylhalides) Alkynes Ketones Amides Nitriles Amines Nitros Aromatics Sulfides (thioethers) Carboxylic acids Thiols (mercaptans) Esters Thiones (thioketones) General naming principles Organic compounds follow a certain naming pattern Prefix = substituent(s) Second Name = type of chain In the naming process we start with the First name: The core skeleton of an organic compound is called its root or parent chain. This refers to the simple skeleton or backbone of the molecule, upon which all the functional groups and substituents are attached. This is the first component to name and identify. The root chain is the longest continuing carbon chain in a molecule. Sometimes the root chain will be written in a simple manner and sometimes the chain will wind and twist. But as long as the carbons are connected, this is considered the parent chain. Then we find the Second name: The second name comes from the saturation of the parent chain, specifically the presence and location of double and triple bonds. These molecules fall into 3 categories: Alkane: Last name -ane Alkene: Last name -ene Alkyne: Last name -yne Then we identify prefixes: 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 >>

Organic Chemistry 1 - Nomenclature

Organic Chemistry 1 - Nomenclature

Sort methane ethane propane butane pentane hexane heptane octane nonane decane undecane dodecane Give the parent chain names for alkanes 1-12 C Continue reading >>

Parent Chain

Parent Chain

How to name organic compounds using the IUPAC rules In order to name organic compounds you must first memorize a few basic names. These names are listed within the discussion of naming alkanes. In general, the base part of the name reflects the number of carbons in what you have assigned to be the . The suffix of the name reflects the type(s) of functional group(s) present on (or within) the parent chain. Other groups which are attached to the parent chain are called substituents. Alkanes - saturated hydrocarbons The names of the straight chain saturated hydrocarbons for up to a 12 carbon chain are shown below. The names of the substituents formed by the removal of one hydrogen from the end of the chain is obtained by changing the suffix -ane to -yl. Number of Carbons Name 1 methane 2 ethane 3 propane 4 butane 5 pentane 6 hexane 7 heptane 8 octane 9 nonane 10 decane 11 undecane 12 dodecane There are a few common branched substituents which you should memorize. These are shown below. Identify the longest carbon chain. This chain is called the parent chain. Identify all of the substituents (groups appending from the parent chain). Number the carbons of the parent chain from the end that gives the substituents the lowest numbers. When compairing a series of numbers, the series that is the "lowest" is the one which contains the lowest number at the occasion of the first difference. If two or more side chains are in equivalent positions, assign the lowest number to the one which will come first in the name. If the same substituent occurs more than once, the location of each point on which the substituent occurs is given. In addition, the number of times the substituent group occurs is indicated by a prefix (di, tri, tetra, etc.). If there are two or more different substituen Continue reading >>

The Names Of Aromatic Compounds

The Names Of Aromatic Compounds

This page looks at the names of some simple aromatic compounds. An aromatic compound is one which contains a benzene ring. It assumes that you are reasonably confident about naming compounds containing chains of carbon atoms (aliphatic compounds). Note: If you aren't sure about naming aliphatic compounds follow this link before you go on. Naming aromatic compounds isn't quite so straightforward as naming chain compounds. Often, more than one name is acceptable and it's not uncommon to find the old names still in use as well. Background The benzene ring All aromatic compounds are based on benzene, C6H6, which has a ring of six carbon atoms and has the symbol: Each corner of the hexagon has a carbon atom with a hydrogen attached. Note: If you don't understand this structure, it is explained in full in two pages on the structure of benzene elsewhere in this site. Following this link could well take you some time! The phenyl group Remember that you get a methyl group, CH3, by removing a hydrogen from methane, CH4. You get a phenyl group, C6H5, by removing a hydrogen from a benzene ring, C6H6. Like a methyl or an ethyl group, a phenyl group is always attached to something else. Aromatic compounds with only one group attached to the benzene ring Cases where the name is based on benzene chlorobenzene This is a simple example of a halogen attached to the benzene ring. The name is self-obvious. The simplified formula for this is C6H5Cl. You could therefore (although you never do!) call it phenyl chloride. Whenever you draw a benzene ring with one other thing attached to it, you are in fact drawing a phenyl group. In order to attach something else, you have to remove one of the existing hydrogen atoms, and so automatically make a phenyl group. nitrobenzene The nitro group, NO2, i Continue reading >>

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