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• A large portion of the materials on plagiarism on the University of Wisconsin Oshkosh's Writing Center Web site was revealed in February to have been taken verbatim from Purdue University's Web page on plagiarism.

Nomenclature of Ethers, Aldehydes, Ketones,

Carboxylic Acids, and Esters

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Ethers and Their Relatives• An ether has two organic groups (alkyl, aryl, or vinyl)

bonded to the same oxygen atom, R–O–R• Diethyl ether is used industrially as a solvent• Tetrahydrofuran (THF) is a solvent that is a cyclic ether• Thiols (R–S–H) and sulfides (R–S–R) are sulfur (for

oxygen) analogs of alcohols and ethers

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Naming Ethers • Simple ethers are named by identifying the two organic

substituents and adding the word ether

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Naming Ethers, continued

•If other functional groups are present, the ether part is considered an alkoxy substituent

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18.9 Crown Ethers

• Large rings consisting repeating (-OCH2CH2-) or similar units

• Named as x-crown-y

– x is the total number of atoms in the ring– y is the number of oxygen atoms– 18-crown-6 ether: 18-membered ring

containing 6 oxygens atoms• Central cavity is electronegative and attracts cations

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18-Crown-6

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Uses of Crown Ethers• Complexes between crown ethers and ionic salts are

soluble in nonpolar organic solvents• Creates reagents that are free of water that have useful

properties• Inorganic salts dissolve in organic solvents leaving the

anion unassociated, enhancing reactivity

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18.10 Thiols and Sulfides

• Thiols (RSH), are sulfur analogs of alcohols

– Named with the suffix -thiol

– SH group is called “mercapto group” (“capturer of mercury”)

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Sulfides

• Sulfides (RSR), are sulfur analogs of ethers

– Named by rules used for ethers, with sulfide in place of ether for simple compounds and alkylthio in place of alkoxy

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Aldehydes and Ketones

• Aldehydes and ketones are characterized by the the carbonyl functional group (C=O)

• The compounds occur widely in nature as intermediates in metabolism and biosynthesis

• They are also common as chemicals, as solvents, monomers, adhesives, agrichemicals and pharmaceuticals

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Naming Aldehydes and Ketones

• Aldehydes are named by replacing the terminal -e of the corresponding alkane name with –al

• The parent chain must contain the CHO group

– The CHO carbon is numbered as C1• If the CHO group is attached to a ring, use the suffix

See Table 19.1 for common names

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Common Name of Some Simple Aldehydes

Formula Common Name Systematic Name

HCHO Formaldehye Methanal

CH3CHO Acetaldehyde Ethanal

CH3CH2CHO Propionaldehyde Propanal

CH3CH2CH2CHO Butyraldehyde Butanal

CH3CH2CH2CH2CHO Valeraldehyde Pentanal

H2C=CHCHO Acrolein Propenal

PhCHO Benzaldehyde Benzenecarbaldehyde

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Naming Ketones• Replace the terminal -e of the alkane name with –one• Parent chain is the longest one that contains the ketone

group

– Numbering begins at the end nearer the carbonyl carbon

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Ketones with Common Names

• IUPAC retains well-used but unsystematic names for a few ketones

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Ketones and Aldehydes as Substituents

• The R–C=O as a substituent is an acyl group is used with the suffix -yl from the root of the carboxylic acid

– CH3CO: acetyl; CHO: formyl; C6H5CO: benzoyl• The prefix oxo- is used if other functional groups are present

and the doubly bonded oxygen is labeled as a substituent on a parent chain

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The Importance of Carboxylic Acids (RCO2H or RCOOH)

• Starting materials for acyl derivatives (esters, amides, and acid chlorides)

• Abundant in nature from oxidation of aldehydes and alcohols in metabolism

– Acetic acid, CH3CO2H, - vinegar

– Butanoic acid, CH3CH2CH2CO2H (rancid butter)

– Long-chain aliphatic acids from the breakdown of fats

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20.1 Naming Carboxylic Acids and Nitriles

• Carboxylic Acids, RCO2H• If derived from open-chain alkanes, replace the terminal

-e of the alkane name with -oic acid• The carboxyl carbon atom is C1

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Alternative Names • Compounds with CO2H bonded to a ring are named

using the suffix -carboxylic acid• The CO2H carbon is not itself numbered in this system• Use common names for formic acid (HCOOH) and acetic

acid (CH3COOH) – see Table 20.1

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Common NamesCommon Names

Systematic NameSystematic Name Common NameCommon NameOO

HCOHHCOH methanoic acidmethanoic acid formic acidformic acid

OO

CHCH33COHCOH ethanoic acidethanoic acid acetic acidacetic acid

OO

CHCH33(CH(CH22))1616COHCOH octadecanoic acidoctadecanoic acid stearic acidstearic acid

– common names are based on natural origin rather than structure

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More Common NamesMore Common Names

Systematic NameSystematic Name Common NameCommon Name

2-hydroxypropanoic2-hydroxypropanoicacidacid

lactic acidlactic acid

((ZZ)-9-octadecenoic)-9-octadecenoicacidacid

oleic acidoleic acid

OO

CHCH33CHCOHCHCOH

OHOH OO

(CH(CH22))77COHCOH

CC CC

HH HH

CHCH33(CH(CH22))77

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Common Diacids

CO OH

CO OH

CO OH

CH2

CO OH

CO OH

CH2

CH2

CO OH

CO OH

CH2

CH2

CH2

CO OH

CO OH

CH2

CH2

CH2

CH2

CO OH

Oxalic Malonic Succinic Glutaric Adipic

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Nitriles, RCN

• Closely related to carboxylic acids named by adding -nitrile as a suffix to the alkane name, with the nitrile carbon numbered C1

• Complex nitriles are named as derivatives of carboxylic acids.

– Replace -ic acid or -oic acid ending with -onitrile

R C N RCNor

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Naming Esters, RCO2R

• Name R’ and then, after a space, the carboxylic acid (RCOOH), with the “-ic acid” ending replaced by “-ate”