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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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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
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
Naming Ethers • Simple ethers are named by identifying the two organic substituents and adding the word ether
Naming Ethers, continued • If other functional groups are present, the ether part is considered an alkoxy substituent
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
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
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”)
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
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
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
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
Ketones with Common Names • IUPAC retains well-used but unsystematic names for a few ketones
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
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
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
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
O HCOH O CH3COH O CH3(CH2)16COH Common Names • common names are based on natural origin rather than structure Systematic Name Common Name methanoic acid formic acid ethanoic acid acetic acid octadecanoic acid stearic acid
O CH3CHCOH O OH CH3(CH2)7 (CH2)7COH C C H H More Common Names Systematic Name Common Name 2-hydroxypropanoicacid lactic acid (Z)-9-octadecenoicacid oleic acid
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
Naming Esters, RCO2R • Name R’ and then, after a space, the carboxylic acid (RCOOH), with the “-ic acid” ending replaced by “-ate”