Organic chemistry 10Word下载.docx

1、-OR（Ar） ester-NH2、-NHR、-NR2 amide2.Naming Carboxylic Acids and DerivativesCarboxylic Acids: RCO2HSimple open-chain carboxylic acids are named by replacing the terminal e of the alkane name with -oic acid. The CO2H carbon （the carboxyl group carbon） is always numbered C1.Alternatively compounds that

2、have a CO2H group bonded to a ring are named by using the suffix -carboxylic acid. In this alternative system, the carboxylic acid carbon is attached to C1 on the ring but is not itself numbered.3-Bromocyclohexanecarboxylic acid1-Cyclopentenecarboxylic acidCommon names Popular name IUPAC name（ -oic

3、acid）HCOOH formic acid methanoic acid CH3COOH acetic acid ethanoic acid HOOC-COOH oxalic acid ethanedioic acid HOOC（CH2）2COOH succinic acidC17H35COOH stearic acid octadecanoic acid C15H31COOH palmitic acid hexadecanoic acid Benzoic acidNomenclature -oic oyl acetyl benzoyl propanoylAcid Halides: RCOX

4、Acid halides are named by identifying first the acyl group and then the halide.The acyl group name is derived from the acid name by replacing the -ic acid ending with -yl, or the -carboxylic acid ending with -carbonyl. For example.Acid Anhydrides: RCO2CORAnhydrides from simple carboxylic acids and c

5、yclic anhydrides from dicarboxylic acids are named by replacing the word acid with anhydride: Acetic anhydride Benzoic anhydride Succinic anhydride acetic propanoic anhydride Amides: RCONH2Amides with an unsubstituted NH2 group are named by replacing the -oic acid or -ic acid ending with -amide or b

6、y replacing the -carboxylic acid ending with carboxamide.If the nitrogen atom is substituted, the amide is named by first identifying the substituent group and then the parent. The substituents are preceded by the letter N to identify them as being directly attached to nitrogen. N,N-dimethylacetamid

7、e N,2-dimethylpropanamide N-phenylacetamide （acetyl aniline）Esters: RCO2RSystematic names for esters are derived by first giving the name of the alkyl group attached to oxygen and then identifying the carboxylic acid. In so doing, the -ic acid ending is replaced by -ate:Nitriles: R-CNCompounds conta

8、ining the CN functional group are called nitriles. Simple acyclic nitriles are named by adding -nitrile as a suffix to the alkane name, with the nitrile carbon numbered C1. More complex nitriles are named as derivatives of carboxylic acids by replacing the -ic acid or -oic acid ending with -onitrile

9、, or by replacing the -carboxylic acid ending with -carbonitrile. In this system, the nitrile carbon atom is attached to C1 but is not itself numbered: Acetonitrile （from acetic acid ） Benzonitrile（from benzoic acid） 2,2-Dimethylcyclohexanecarbonitrile （from 2,2-dimethylcyclohexanecarboxylic acid）3.

10、Occurrence and Properties of Carboxylic AcidsThe most obvious property of carboxylic acids is implied by their name-their acidity. Carboxylic acids are much stronger acids than alcohols. Acetic acid: Ka = 1.76 10-5 （pKa = 4.75） Ethanol: Ka = 10-16 （pKa = 16）.carboxylic acids react with bases such as

11、 NaOH to give water-soluble metal carboxylates, RCO2- Na+. RCOOH H2CO3 ArOH 酸性大小的判断：1吸电子能力越高基团的取代烃基上的H则酸性越强2吸电子基团越多，酸性越强3吸电子基团离羰基越近，则酸性越强4斥电子基团越多，越大，则酸性越小4. Nucleophilic Acyl Substitution ReactionsCarboxylic acids and their derivatives also react with nucleophiles, but the ultimate product is differ

12、ent from that of the aldehyde/ketone reaction. In comparing the reactivity of different acyl derivatives, the more electron-poor the C=O carbon, the more readily the compound reacts with nucleophiles.A consequence of these reactivity differences is that its usually possible to convert a more reactiv

13、e acid derivative into a less reactive one. Acid chlorides, for example, can be converted into esters and amides, but amides and esters cant be converted into acid chlorides. 5.Reactions of Carboxylic Acids.Conversion of Acids into Alcohols by Reduction（RCO2H RCH2OH）carboxylic acids are reduced by l

14、ithium aluminum hydride （LiAlH4） to yield primary alcohols.Formation of carboxylic acid derivativesacyl Acetyl （-ic -yl） Conversion of Acids into Acid Chlorides （RCO2H RCOCl）Carboxylic acids are converted into acid chlorides by treatment with thionyl chloride, SOCl2. The net effect is substitution o

15、f the -OH group by -Cl. For example:acyl halide or acid halideConversion of Acids into Esters （RCO2H RCO2R）Perhaps the most useful reaction of carboxylic acids is their conversion into esters by reaction with an alcohol-the substitution of -OH by -OR.Called the Fischer esterification reaction, the s

16、implest method involves heating the carboxylic acid with an acid catalyst in an alcohol solvent.ester （esterification）Alcohols: CH3OH 10 2030Carboxylic acid: HCOOH CH3COOH RCH2COOH R2CHCOOH R3CCOOHacid anhydrideCyclic acid anhydride amide6.Chemistry of Acid HalidesConversion of Acid Chlorides into A

17、cids （RCOCl RCO2H）Acid chlorides react with water to yield carboxylic acids （hydrolysis reaction）.Conversion of Acid Chlorides Into Esters （RCOClRCO2RAcid chlorides react with alcohols to yield esters in a reaction analogous to their reaction with water to yield acids:Conversion of Acid Chlorides in

18、to Amides （RCOCl RCONH2）Acid chlorides react rapidly with ammonia and with amines to give amides.7.Chemistry of Acid AnhydridesThe best method for preparing acid anhydrides is by a nucleophilic acyl substitution reaction of an acid chloride with a carboxylic acid anion. Acetic anhydride is often use

19、d to prepare acetate esters of complex alcohols and to prepare substituted acetamides from amines.The chemistry of acid anhydrides is similar to that of acid chlorides. 8.Chemistry of EstersConversion of Esters into Acids （RCO2R RCO2H）Esters are hydrolyzed either by aqueous base or by aqueous acid t

20、o yield a carboxylic acid plus an alcohol:Hydrolysis in basic solution is called saponification.soap is made by the base-induced ester hydrolysis of animal fatConversion of Esters into Alcohols by Reduction （RCO2R RCH2OH）Esters are reduced by treatment with LiAlH4 to yield primary alcohol.Conversion

21、 of Esters into Alcohols by Reaction with Grignard Reagents.Grignard reagents react with esters to yield tertiary alcohols in which two of the substituents on the hydroxyl-bearing carbon are identical.9.Chemistry of amidesConversion of Amides Into Acids （RCONH2 RCO2H）Amides undergo hydrolysis to yie

22、ld carboxylic acids plus amine on heating in either aqueous acid or base. Conversion of Amides into Amines by Reduction （RCONH2 RCH2NH2）Like other carboxylic acid derivatives, amides are reduced by LiAlH4. The product of this reduction, however, is an amine rather than an alcohol:This kind of reaction is specific for amides and does not occur with other carboxylic acid derivatives.Summarychemical propertiesnucleophilic substitutionHNu: reaction H2O hydrolysis ROH alcoholysis NH3（H2NR） ammonolysis 1）hydrolysis2） alcoholysis 3） Ammonolysis （NH3、H2NR、HNR2）