Chemistry 121 Winter 17 Introduction to Organic Chemistry and Biochemistry Instructor Dr. Upali Siriwardane (Ph.D. Ohio State) E-mail: upali@latech.edu Office: 311 Carson Taylor Hall ; Phone: 318-257-4941; Contact me trough e-mail if you have questions December 16, 2016: Test 1 (Chapters 12-13) January 23, 2017 : Test 2 (Chapters 14-16) February 10, 2017 : Test 3 (Chapters 17-19) February 22, 2017 : Test 4 (Chapters 20-22) February 23, 2017: Make Up Exam: Chapters 12-22)

Chapter 16 and GHW#6 Questions Carboxylic Acids, Esters, and Other Acid Derivatives

Chapter 16: Carboxylic Acids, Esters, and Other Acid Derivatives 16-1Structure of Carboxylic Acids and Their Derivatives Carbonyl Compounds and Acyl Compounds 16-2IUPAC Nomenclature for Carboxylic Acids 16-3Common Names for Carboxylic Acids Monocarboxylic Acids 16-4Polyfunctional Carboxylic Acids 16-5Physical Properties of Carboxylic Acids 16-6Preparation of Carboxylic Acids 16-7Acidity of Carboxylic Acids 16-8Carboxylic Acid Salts Uses for Carboxylic Acid Salts 16-9Carboxylic Acid Decarboxylation Reaction 16-10Structure of Esters 16-11Preparation of Esters Cyclic Esters (Lactones) 16-12Nomenclature for Esters 16-13Selected Common Esters 16-14Isomerism for Carboxylic Acids and Esters 16-15Physical Properties of Esters 16-16Chemical Reactions of Esters 16-17Sulfur Analogs of Esters 16-18Polyesters 16-19Acid Chlorides and Acid Anhydrides 16-20Esters and Anhydrides of Inorganic Acids

Bonding Characteristics of Carboxylic Acids A carboxylic acid has functional a carboxyl group. A carboxyl group is a carbonyl group (C=O) with a hydroxo group (—OH) bonded to the carboxyl carbon atom.

Physical Properties of Carboxylic Acids Both polar molecules and hydrogen bonding makes: BP and MP are higher than alcohols , hydrocarbons and ether with comparable carbon numbers

Acidity

Physical Properties of carboxylic acids derivatives Esters, amides, acid chlorides and acid anhydride have lower boiling and melting points than parent acid, Except Carboxylic Acid Salts

IUPAC Nomenclature of Carboxylic Acid and Esters The IUPAC system deals with functional groups two different ways. Modification of the hydrocarbon name to indicate the presence of a functional group. Acid – R-COOH use -oic ending. Esters –R-COOR’ use -oate ending.

Common Names of Carboxylic Acids

IUPAC Nomenclature of Carboxylic Acid and Esters

Carboxylic Acids

Esters as Flavors

Common/IUPAC Nomenclature of Esters

Nomenclature of Carboxylate salts Metal alkanoate (-oate suffix for anion) E.g. sodium salt of proponoic acid is named as sodium proponate

Nomenclature of Acid Anhydrides Alkanoic anhydride (-oic anhydride suffix) E.g. anhydride of proponoic acid is named as proponoic anhydride Mixed acid anhydride are name butanoic proponoic anhydirdes

1. Identify the carboxylic acids, esters, amides and acid from the following and give their common and/or IUPAC names. Carboxylic Acids, Esters, and Other Acid Derivatives a)Type:___________ Name:____________ b) Type:_________________ Name:__________________ c)Type:_________________ d)Type:___________ e)Type:_________________ f)Type:_________________

1. Identify the carboxylic acids, esters, amides and acid from the following and give their common and/or IUPAC names. Carboxylic Acids, Esters, and Other Acid Derivatives g) Type:________________ Name:__________________ h) Type:___________________ i)

2. Draw the condensed formula of following carboxylic acid and their derivatives. a) methyl propanoate   b) ethyl pentanoate c) propanoyl chloride d) N-methyl propanamide e) N,N-dimethyl ethanamide f) 2-methyl pentanamide g) 2(a)-aminopropanoic h) butanoic ethanoic anhydride

Polyfunctional Carboxylic Acids Dicarboxylic acids Oh my, such great apple pie!“ (oxalic, malonic, succinic, glutaric, adipic, pimelic) "Metabolic" Acids Propionic acid, (C3 mono acids): lactic, glyceric, and pyruvic acids Succinic acid (C4 diacid): fumaric, oxaloacetic, and malic acids Glutaric acid (C5 diacid): a-ketoglutaric and citric acids

3. Identify type and give name of each of the following poly functional carboxylic acids. Type:______________Name:_____________ c) Type:_______________ Name:______________ d) Type:________________Nmee:_______________ e) Type:__________Name:__________ f) Type:____________Name:___________

IUPAC:_______________ e) Common:___________ 3. Give common/IUPAC names of following dicarboxylic acids. Use "Oh my, such great apple pie!" (oxalic, malonic, succinic, glutaric, adipic, pimelic). a) Common:___________ IUPAC:_______________ b) Common:___________ c) Common:____________ d) IUPAC:_____________ e) Common:___________

3. Give common/IUPAC names of following dicarboxylic acids. f) Name:______________ g) Name:__________ h)Common:__________ IUPAC:______________

Saturated Fatty Acids Long chain even carbon atoms C >10

Unsaturated Fatty Acids Long chain even carbon atoms with C=C bonds

5. Give type/name of following fatty acids, and their derivatives. CH3(CH2)10CO2H Type:_______________ Name:______________ b) CH3(CH2)14CO2H Type:________________ Name:_______________ c) CH3(CH2)16CO2H

d) CH3(CH2)7CH=CH(CH2)7CO2H 5. Give type/name of following fatty acids, and their derivatives. d) CH3(CH2)7CH=CH(CH2)7CO2H Type:________________ Name:_______________ e) f) Type:________________ Name:________________ Type:_______________ Name:___________ d) H3(CH2)7CH=CH(CH2)7CO2H e) Type:________________ Name:_______________ f)

Triglycerides: Triesters of glycerol

Preparation of Carboxylic Acids Oxidation of primary alcohol to carboxylic acid (described in reactions of alcohols) Tollen’s Oxidation using  basic Ag(NH3)2+ or Bendict’s CuSO4/Na2CO2/Citrate (described in reactions of aldehydes) Oxidation of alkyl side chain of substituted aromatic hydrocarbons (reactions of aromatic alkyl compounds) Hydrolysis of esters. (Described in this chaper) Hydrolysis of acid, amides and cholrides etc.. )

Oxidation of Alcohols to Carboxylic Acids Non-aromatic carboxylic acids: Oxidation of primary alcohols or aldehydes, using an oxidizing agent such as K2Cr2O7 Aromatic carboxylic acids: Oxidation of a carbon side chain (alkyl group) on a benzene derivative Examples:

Oxidation of primary alcohols

Oxidation of Aldehydes Tollen’s and Benedict’s Oxidation of alkyl side chain substituted on a benzene ring

Chemical Reactions of Carboxylic Acids Reduction to alcohols with reducing agents (LiAlH4, NaBH4 etc.) Reaction with halogen compounds to form acid chlorides(described below in preparation of acid chloride preparations) Reaction with strong bases to form acid salts (described below in preparation of acid salts) Reaction with strong alcohols to form esters (described below in preparation of esters) Reaction with ammonia and amine compounds to form amides (described in amides chapter 17)

Carboxylic Acid Reduction: To alcohols

Acid chloride Formation

Preparation of esters. Esterification acid + alcohol ----> ester + H2O

Amide Formation (Cl)

6) Name and complete following reactions 1) 2) 3) 4)

6) Name and complete following reactions 5) 6)

Polyesters Polymers are formed by reacting difunctional monomers Examples: dicarboxylic acids and dialcohols are used for the formation of polyesters Two important polymers: Poly(ethylene terephthalate) (PET) Lactomer

Poly(ethylene terephthalate) Poly(ethylene terephthalate) (PET): Prepared by reacting terephthalic acid (a diacid) and ethylene glycol (a dialcohol) Used for making textiles and other plastic applications

Biodgradable Polymers Lactomer: Used in surgical staples because of its biodgradable nature It simply dissolves after several weeks and the by-products formed are lactic acid and glycolic acid both of which are part of human body

7) Name and complete following reactions. Condensation Polymerization 2) Aspirin synthesis

Cyclic Esters (Lactones) Hydroxy acids contain both a hydroxyl and a carboxyl group and such compounds have the capacity to undergo intermolecular esterification to form cyclic esters Takes place in situations where a five- or six-membered ring can be formed Cyclic esters are called lactones 43

7) Name and complete following reactions. 3) Cyclic ester formation 4) Decarboxylation of b- ketoacids

Fatty acids and Glycerides

7) Name and complete following reactions. 5) Base hydrolysis of esters 6) Base hydrolysis of triglycerides

Base hydrolysis of triglycerides Saponification-Soap formation