有机英文命名

3 NOMENCLATURE OF ORGANIC COMPOUNDSA complete discussion of definitive rules of organic nomenclature would require more space than can be allotted in this text. We will survey some of the more common nomenclature rules, both IUPAC and trivial.AlkanesThe names for the first twenty continuous-chain alkanes are listed in Table 1.Table 1 Names of continuous-chain alkanes CH4Methane C11H24undecaneC2H6Ethane C12H26dodecaneC3H8Propane C13H28tridecaneC4H10Butane C14H30tetradecaneC5H12Pentane C15H32pentadecaneC6H14Hexane C16H34hexadecaneC7H16Heptane C17H36HeptadecaneC8H18Octane C18H38OctadecaneC9H20Nonane C19H40NonadecaneC10H22Decane C20H42EicosaneAlkenes and AlkynesUnbranched hydrocarbons having one double bond are named in the IUPAC system by replacing the ending -ane of the alkane name with -ene. If there are two or more double bonds, the ending is -adiene, -atriene, etc.Unbranched hydrocarbons having one triple bond are named by replacing the ending -ane of the alkane name with -yne. If there are two or more triple bonds, the ending is -adiyne,-atriyne etc. Table 2 shows names for some alkyl groups, alkanes, alkenes and alkynes.Table 2 Some Alkanes, Alkyl, Alkenes,AlkynesAlkanes Alkyls Alkenes alkynesIUPAC CommonMthane MethylEthane Ethyl Ethene Ethylene Acetylene Propane Propyl Propene Propylene Propyne Butane Butyl Butene Butylene Butyne Pentane PentylPentene Pentylene Pentyne (amyl)Hexane HexylHeptane HeptylOctane OctylNonane NonylDecane Decyl-ane-yl-ene-ene-yneThe PrefixesIn the IUPAC system, alkyl and aryl substituents and many functional groups are named as prefixes on the parent (for example, iodomethane). Some common functional groups named as prefixes are listed in Table 3.Table 3 Some Functional Groups Named as PrefixesStructure Name-OR Alkoxy- *-NH2Amino--N=N-Azo--Br Bromo--Cl Chloro--F Fluoro--H Hydro--I Iodo--NO2Nitro--NO Nitroso-* methoxy-, ethoxy-, etc., depending upon the R groupIn simple compounds, the prefixes di-, tri-, tetra-, penta-, hexa-, etc. are used to indicate the number of times a substituent is found in the structure: e.g., dimethylamine for (CH3)2NH or dichloromethane for CH2Cl2.In complex structures, the prefixes bis-, tris-, and tetrakis- are used: bis- means two of a kind; tris-, three of a kind; and tetrakis-, four of a kind. [(CH3)2N]2 is bis(dimethylamino) and not di(dimethylamino). Nomenclature Priority of Functional GroupsIn naming a compound, the longest chain containing principal functional group is considered the parent. The parent is numbered from the principal functional group to the other end, the direction being chosen to give the lowest numbers to the substituents. The entire name of the structure is then composed of (1) the numbers of the positions of the substituts (and of the principal functional group, if necessary); (2) the names of the substituts; (3) the name of the parent.The various functional groups are ranked in priority as to which receives the suffix name and the lowest position number .A list of these priorities is given in Table 4.Table 4 Nomenclature Priority*Structure Name-N(CH3)3+ (as one example)Onium ion-CO2H Carboxylic acid-SO3H Sulfonic acid-COX Acid halide-CONR2Amide-CN Nitrile-CHO Aldehyde-CO-KetoneROH AlcoholArOH Phenol-SH Thiol-NR2Amine-O-O-Peroxide-MgX (as one example)Organometallic> C=C<alkene-C C-alkyneR-, X-, etc.other substituents * Highest priority is at top.KetonesIn the systematic names for ketones, the -e of the parent alkane name is dropped and -one is added. A prefix number is used if necessary.In a complex structure, a ketone group my be named in IUPAC system with the prefix oxo-. (The prefix keto- is also sometimes encountered.)AlcoholsThe names of alcohols may be: (1) IUPAC; (2) trivial; or, occasionally, (3) conjunctive. IUPAC names are taken from the name of the alkane with the final -e changed to -ol. In the case of polyols, the prefix di-, tri- etc. is placed just before -ol, with the position numbers placed at the start of the name, if possible, such as, 1,4-cyclohexandiol. Names for some alkyl halides, ketones and alcohols are listed in Table 5.Table 5 Some Alkyl halides, Ketones and AlcoholsAlkyl halides Ketones AlcoholsIUPAC COMMONChloromethane Methyl chloride MethanolBromoethane Ethyl bromide EthanolFluropropane Propyl fluoride Acetone PropanolIodobutane Butyl iodide Butanone ButanolPentanone Pentanol-one-olEthersEthers are usually named by using the names of attached alkyl or aryl groups followed by the word ether. (These are trivial names.) For example, diethyl ether.In more complex ethers, an alkoxy- prefix may be used. This is the IUPAC preference, such as 3-methoxyhexane. Sometimes the prefix- oxa- is used.AminesAmines are named in two principal ways: with -amine as the ending and with amino- as a prefix. Names for some ethers and amines can be found in Table 6.Table 6 Names for Some Ethers and AminesEthers Amines COMMON IUPAC COMMON IUPACDimethylether1-methoxy-propane Methylamine AminomethaneMethyl ethyl ether 2-ethoxy-pentane Diethylamine2-amino-butaneEthoxy-cyclo-Hexane Ethyl-methylamineDimethylaminoethaneCarboxylic AcidsThere are four principal types of names for carboxylic acids: (1) IUPAC;(2)trivial; (3)carboxylic acid; and (4)conjunctive. Trivial names are commonly used.AldehydesAldehydes may be named by the IUPAC system or by trivial aldehyde names. In the IUPAC system, the -oic acid ending of the corresponding carboxylic acid is changed to -al, such as hexanal. In trivial names, the -ic or -oic ending is changed to -aldehyde, such as benzaldehyde. Table 7 gives a list of commonly encountered names for carboxylic acids and aldehydes.Table 7 Names of Some Carboxylic Acids and AldehydesCarboxylic acids Acids Aldehydes Common IUPAC Common IUPAC Formic acid Methanoic acid Formaldehyde Formyl-(-CHO) Acetic acid Ethanoic acid AcetaldehydePropionic acid Propanoic acid Propionaldehyde Propanal Butyric acid Butanoic acid ButyraldehydeValeric acid Pentanoic acidCaproic acid Hexanoic acid hexanalOenanthic acid Heptanoic acidCaprylic acid Octanoic acid octanal Pelargonic acid Nonanoic acidCapric acid Decanoic acid decanal Esters and Salts of Carboxylic AcidsEsters and salts of carboxylic acids are named as two words in both systematic and trivial names. The first word of the name is the name of the substituent on the oxygen. The second word of the name is derived from the name of the parent carboxylic acid with the ending changed from -ic acid to -ate.AmidesIn both the IUPAC and trivial systems, an amide is named by dropping the -ic or -oic ending of the corresponding acid name and adding -amide, such as hexanamide (IUPAC) and acetamide (trivial).Acid AnhydridesAcid anhydrides are named from the names of the component acid or acids with the word acid dropped and the word anhydride added, such as benzoic anhydride.The names for some esters, amides and anhydrides are shown in Table 8.Table 8 Some Esters, Amides and Anhydrides Esters Amides AnhydridesCommon IUPACMethylformateFormamideEthylacetateAcetic anhydride Propionamide PropanamidePropyl butyrate N-methylbutyramideButanamide Acetic formicanhydrideAcid HalidesAcid halides are named by changing the ending of the carboxylic acid name from -ic acid to -yl plus the name of the halide, such as acetyl chloride.Some names of aryl compounds and aryls are as follows:benzenephenylbenzylarylbenzoic acid译文:3. 有机化合物的命名法对有机化合物的命名规则作一个完整的讨论将需要比本文所允许的多得多的篇幅。