5-MED101_Carboxylic_acids_their_derivatives_pptx

MED100 MOLECULAR AND CELLULAR MEDICAL SCIENCES I Asst. Prof. Behiye ÖZTÜRK ŞEN [email protected]  Carbonyl Compounds A sk organic chemists about functional g...

MED100 MOLECULAR AND CELLULAR MEDICAL SCIENCES I Asst. Prof. Behiye ÖZTÜRK ŞEN [email protected]  Carbonyl Compounds A sk organic chemists about functional group, and a good percentage of them will name a their favorite group that contains a carbonyl group. Why? Because carbonyl groups are at the heart of many key functional groups, including aldehydes, ketones, carboxylic acids, and amides. Moreover, carbonyl groups are versatile, serving as a nexus for interconversions between many other kinds of functional groups. Altınbas University Lecturer: Asst. Prof. Behiye ÖZTÜRK ŞEN [email protected] MED101 MOLECULLAR AND CELLULAR MEDICAL SCIENCES I  Lecture Presentation Carboxylic acids & Their Derivatives Altınbas University Lecturer: Asst. Prof. Behiye ÖZTÜRK ŞEN [email protected] MED101 MOLECULLAR AND CELLULAR MEDICAL SCIENCES I In this Chapter; You will learn Chemical Bonds: The Octet Rule Ionic Bonds Covalent Bonds and Lewis Structures How To Write Lewis Structures Exceptions to the Octet Rule Formal Charges and How To Calculate Them A Summary of Formal Charges How To Write and Interpret Structural Formulas More About Dash Structural Formulas Condensed Structural Formulas Rules for Writing Resonance Structures  Structure of the Carbonyl Group Carbonyl compounds are a broad group of compounds that includes aldehydes, ketones, carboxylic acids, esters, and amides Altınbas University Lecturer: Asst. Prof. Behiye ÖZTÜRK ŞEN [email protected] MED101 MOLECULLAR AND CELLULAR MEDICAL SCIENCES I  Structure of the Carbonyl Group Altınbas University Lecturer: Asst. Prof. Behiye ÖZTÜRK ŞEN [email protected] MED101 MOLECULLAR AND CELLULAR MEDICAL SCIENCES I  Vanillin is responsible for the smell of vanilla, while almond flavor results from benzaldehyde, cinnamon from cinnamaldehyde, and spearmint from (R)-carvone. Other odors and sensations that are far less pleasant can also be caused by aldehydes and ketones—for example, the pungent odor of formaldehyde or acetone, or the hangover caused by acetaldehyde that results from drinking too many alcoholic beverages Altınbas University Lecturer: Asst. Prof. Behiye ÖZTÜRK ŞEN [email protected] MED101 MOLECULLAR AND CELLULAR MEDICAL SCIENCES I  Aldehydes and Ketones Aldehydes have a carbonyl group bonded to a carbon atom on one side and a hydrogen atom on the other side. (Formaldehyde is an exception because it has hydrogen atoms on both sides.) Ketones have a carbonyl group bonded to carbon atoms on both sides. Altınbas University Lecturer: Asst. Prof. Behiye ÖZTÜRK ŞEN [email protected] MED101 MOLECULLAR AND CELLULAR MEDICAL SCIENCES I  Nomenclature of Aldehydes and Ketones Aliphatic aldehydes are named substitutively in the IUPAC system by replacing the final -e of the name of the corresponding alkane with -al Since the aldehyde group must be at an end of the carbon chain, there is no need to indicate its position. When other substituents are present the carbonyl group carbon is assigned position 1. Many aldehydes also have common names; these are given below in parentheses. These common names are derived from the common names for the corresponding carboxylic acids, and some of them are retained by the IUPAC as acceptable names. Altınbas University Lecturer: Asst. Prof. Behiye ÖZTÜRK ŞEN [email protected] MED101 MOLECULLAR AND CELLULAR MEDICAL SCIENCES I  Nomenclature of Aldehydes and Ketones Altınbas University Lecturer: Asst. Prof. Behiye ÖZTÜRK ŞEN [email protected] MED101 MOLECULLAR AND CELLULAR MEDICAL SCIENCES I  Nomenclature of Aldehydes and Ketones Aldehydes in which the −CHO group is attached to a ring system are named substitutively by adding the suffix carbaldehyde. Several examples follow: Altınbas University Lecturer: Asst. Prof. Behiye ÖZTÜRK ŞEN [email protected] MED101 MOLECULLAR AND CELLULAR MEDICAL SCIENCES I  Nomenclature of Aldehydes and Ketones The common name benzaldehyde is far more frequently used than benzenecarbaldehyde for C6H5CHO, and it is the name we shall use in this text. Aliphatic ketones are named substitutively by replacing the final -e of the name of the corresponding alkane with -one. The chain is then numbered in the way that gives the carbonyl carbon atom the lower possible number, and this number is used to designate its position. Altınbas University Lecturer: Asst. Prof. Behiye ÖZTÜRK ŞEN [email protected] MED101 MOLECULLAR AND CELLULAR MEDICAL SCIENCES I  Nomenclature of Aldehydes and Ketones Common functional group names for ketones (in parentheses above) are obtained simply by separately naming the two groups attached to the carbonyl group and adding the word ketone as a separate word. Altınbas University Lecturer: Asst. Prof. Behiye ÖZTÜRK ŞEN [email protected] MED101 MOLECULLAR AND CELLULAR MEDICAL SCIENCES I  Nomenclature of Aldehydes and Ketones Some ketones have common names that are retained in the IUPAC system: Altınbas University Lecturer: Asst. Prof. Behiye ÖZTÜRK ŞEN [email protected] MED101 MOLECULLAR AND CELLULAR MEDICAL SCIENCES I  Nomenclature of Aldehydes and Ketones Exercises: Give a structural formula and another acceptable name for each of the following compounds: a) Formaldehyde b) Acetaldehyde c) Phenylacetaldehyde d) Acetone e) Ethyl methyl ketone f) Acetophenone g) Benzophenone h) Diethyl ketone i) Ethyl isopropyl ketone j) Diisopropyl ketone k) Dibutyl ketone l) Dipropyl ketone Altınbas University Lecturer: Asst. Prof. Behiye ÖZTÜRK ŞEN [email protected] MED101 MOLECULLAR AND CELLULAR MEDICAL SCIENCES I Altınbas University Lecturer: Asst. Prof. Behiye ÖZTÜRK ŞEN [email protected] MED101 MOLECULLAR AND CELLULAR MEDICAL SCIENCES I  Carboxylic Acid and Derivatives Altınbas University Lecturer: Asst. Prof. Behiye ÖZTÜRK ŞEN [email protected] MED101 MOLECULLAR AND CELLULAR MEDICAL SCIENCES I  Nomenclature of Carboxylic Acids Systematic or substitutive names for carboxylic acids are obtained by dropping the final -e of the name of the alkane corresponding to the longest chain in the acid and by adding -oic acid. The carboxyl carbon atom is assigned number 1. Altınbas University Lecturer: Asst. Prof. Behiye ÖZTÜRK ŞEN [email protected] MED101 MOLECULLAR AND CELLULAR MEDICAL SCIENCES I  Properties of Carboxylic Acids ✔ Carboxylic acids are polar substances. ✔ Their molecules can form strong hydrogen bonds with each other and with water. ✔ As a result, carboxylic acids generally have high boiling points, and low-molecular- weight carboxylic acids show appreciable solubility in water. ✔ As the length of the carbon chain increases, water solubility declines Altınbas University Lecturer: Asst. Prof. Behiye ÖZTÜRK ŞEN [email protected] MED101 MOLECULLAR AND CELLULAR MEDICAL SCIENCES I  Nomenclature of Carboxylic Acids Exercises: Give an IUPAC systematic name for each of the following: Altınbas University Lecturer: Asst. Prof. Behiye ÖZTÜRK ŞEN [email protected] MED101 MOLECULLAR AND CELLULAR MEDICAL SCIENCES I  Esters The names of esters are derived from the names of the alcohol (with the ending -yl) and the acid (with the ending -ate or -oate). The portion of the name derived from the alcohol comes first: Altınbas University Lecturer: Asst. Prof. Behiye ÖZTÜRK ŞEN [email protected] MED101 MOLECULLAR AND CELLULAR MEDICAL SCIENCES I  Esters Esters are polar compounds, but lacking a hydrogen attached to oxygen, their molecules cannot form strong hydrogen bonds to each other. As a result, esters have boiling points that are lower than those of acids and alcohols of comparable molecular weight. The boiling points of esters are about the same as those of comparable aldehydes and ketones. Unlike the low-molecular-weight acids, esters usually have pleasant odors, some resembling those of fruits, and these are used in the manufacture of synthetic flavors: Altınbas University Lecturer: Asst. Prof. Behiye ÖZTÜRK ŞEN [email protected] MED101 MOLECULLAR AND CELLULAR MEDICAL SCIENCES I  Amides Amides that have no substituent on nitrogen are named by dropping -ic acid from the common name of the acid (or -oic acid from the substitutive name) and then adding -amide. Alkyl groups on the nitrogen atom of amides are named as substituents, and the named substituent is prefaced by N- or N,N-. Examples are Altınbas University Lecturer: Asst. Prof. Behiye ÖZTÜRK ŞEN [email protected] MED101 MOLECULLAR AND CELLULAR MEDICAL SCIENCES I  Amides Amides with nitrogen atoms bearing one or two hydrogen atoms are able to form strong hydrogen bonds to each other. Such amides have high melting points and boiling points. On the other hand, molecules of N,N- disubstituted amides cannot form strong hydrogen bonds to each other, and they have lower melting points and boiling points. The melting and boiling data given above illustrate this trend. Hydrogen bonding between amide groups plays a key role in the way proteins and peptides fold to achieve their overall shape. Altınbas University Lecturer: Asst. Prof. Behiye ÖZTÜRK ŞEN [email protected] MED101 MOLECULLAR AND CELLULAR MEDICAL SCIENCES I  Amides Proteins and peptides (short proteins) are polymers of amino acids joined by amide groups. One feature common to the structure of many proteins is the β sheet, shown below: Altınbas University Lecturer: Asst. Prof. Behiye ÖZTÜRK ŞEN [email protected] MED101 MOLECULLAR AND CELLULAR MEDICAL SCIENCES I  Amides Exercises: Write structural formulas for the following: a) Methyl propanoate b) Ethyl p-nitrobenzoate c) N,N-Dimethylbenzamide d) N,N-Dimethylformamide e) 2-Bromopropanoyl bromide Altınbas University Lecturer: Asst. Prof. Behiye ÖZTÜRK ŞEN [email protected] MED101 MOLECULLAR AND CELLULAR MEDICAL SCIENCES I  Amine-containing compounds have an incredible range of biochemical properties. Some, like acetylcholine, act as neurotransmitters, control muscle function, enhance sensory perceptions, and sustain attention span. Others play far more sinister roles. Colombian poison dart frogs, for example, are tiny and beautiful, but they are also deadly. They produce a compound known as histrionicotoxin, an amine that causes paralysis and eventually death through suffocation. The respiratory muscles cease to function because acetylcholine cannot act, preventing it from initiating the electrical signaling that makes the muscles of our lungs function. Altınbas University Lecturer: Asst. Prof. Behiye ÖZTÜRK ŞEN [email protected] MED101 MOLECULLAR AND CELLULAR MEDICAL SCIENCES I Altınbas University Lecturer: Asst. Prof. Behiye ÖZTÜRK ŞEN [email protected] MED101 MOLECULLAR AND CELLULAR MEDICAL SCIENCES I  Nomenclature of Amines In common nomenclature most primary amines are named as alkylamines. In systematic nomenclature (blue names in parentheses below) they are named by adding the suffix -amine to the name of the chain or ring system to which the NH2 group is attached with replacement of the final -e. Amines are classified as being primary (1°), secondary (2°), or tertiary (3°) on the basis of the number of organic groups attached to the nitrogen. PRIMARY AMINES Altınbas University Lecturer: Asst. Prof. Behiye ÖZTÜRK ŞEN [email protected] MED101 MOLECULLAR AND CELLULAR MEDICAL SCIENCES I  Nomenclature of Amines Most secondary and tertiary amines are named in the same general way. In common nomenclature we either designate the organic groups individually if they are different or use the prefixes di- or tri- if they are the same. In systematic nomenclature we use the locant N to designate substituents attached to a nitrogen atom. SECONDARY AMINES Altınbas University Lecturer: Asst. Prof. Behiye ÖZTÜRK ŞEN [email protected] MED101 MOLECULLAR AND CELLULAR MEDICAL SCIENCES I  Nomenclature of Amines TERTIARY AMINES Altınbas University Lecturer: Asst. Prof. Behiye ÖZTÜRK ŞEN [email protected] MED101 MOLECULLAR AND CELLULAR MEDICAL SCIENCES I  Nomenclature of Amines In the IUPAC system, the substituent −NH2 is called the amino group. We often use this system for naming amines containing an OH group or a CO2H group: Altınbas University Lecturer: Asst. Prof. Behiye ÖZTÜRK ŞEN [email protected] MED101 MOLECULLAR AND CELLULAR MEDICAL SCIENCES I Altınbas University Lecturer: Asst. Prof. Behiye ÖZTÜRK ŞEN [email protected] MED101 MOLECULLAR AND CELLULAR MEDICAL SCIENCES I