Livestock science and animal production technologies

Learning objectives

To introduce the student to the basic concepts of Organic Chemistry and to the
properties and reactivity of the different classes of organic compounds.

Prerequisites

To successfully follow the course and pass the examination it is fundamental to
possess most of the knowledge and concepts treated in the course of 'Chimica
Generale'. In particular, fundamental are the concepts related to the electronic
structure of the atoms, to the chemical bond, to thermodynamics (with special
regard to the chemical equilibria and to acid-base equilibria) and to the chemical
kinetics.
It is not compulsory to have passed the examination of Chimica Generale, but it is
strongly recommended to be in possess of most of the concepts related to such
course before attending the lectures of Chimica Organica.

Course unit content

The students will be first introduced to the basic theories of VSEPR and of the
valence bond for the description of organic molecules. Some basic concepts of
chemical thermodynamics and kinetics will be also reminded with particular
attention to 1st and 2nd order reactions, to chemical catalysis and to competitive
reactions. The concepts of nucleophile and electrophile will be compared with those
of Brønsted-Lowry and Lewis acid and base. The concepts of organic
stereochemistry will be described together with the stereochemical nomenclature
and properties of the stereoisomers with particular attention to biological and
pharmaceutical world.
A systematic survey of the structure, properties and reactivity of organic molecules,
divided by functional groups, will be undertaken. In particular this analysis will
include the following classes of organic compounds: Alkanes snd Cycloalkanes;
Alkenes and Alkynes; Alkyl halides; Alcohols, Ethers and Thiols; Benzenes and
Aromatic compounds; Amines; Ketones and Aldehydes; Carboxylic acids and their
derivatives.
In parallel to this theoretical part, a series of exercises will be presented and solved
during separate tutoring lectures aiming at applying the concepts learnt and to
provide a constructivist approach to learning organic chemistry.

Full programme

Introduction

Introduction to Organic Chemistry; The C atom as central atom in organic compounds; electronic and Lewis structures of atoms; Lewis bond model; electronegativity; Lewis structures of molecules and ions; bond angles and distances: shape of molecules according to the VSEPR theory; dipole moment of bonds and molecules; resonance. Covalent bonds according to the valence bond theory: hybridation of atomic orbitals. Introduction to the functional group theory. Intermolecular forces (dipole-dipole interactions, Hydrogen bonds, van der Waals forces); polarizability; solubility and physical properties of organic compounds; properties of solvents (apolar, dipolar aprotic and protic solvents); dielectric constants of solvents.
Fundamentals of kinetics. First and second order reactions. Molecularity of a reaction. Effect of the temperature on the rate of a reaction: Arrhenius equation.
Thermodynamics and kinetics of organic reactions
Enthalpy and entropy of reaction. Kinetics of reactions: mechanism of a reaction, rate determing steps, reaction intermediates, transition states and activation energy; rate of a reaction and specific rate constant; molecularity; Eyring equation. Chemical catalysis. Reactions under kinetic or thermodynamic control. Competitive reactions. Hammond postulate. Brønsted-Lowry acids and bases. Nucleophiles and electrophiles.
Structure analysis: properties and reactivity according to functional group theory.

Alkanes. Nomenclature. Cycloalkanes. Nomenclature. Conformation of alkanes. Conformation of cycloalkanes and substituted cycloalkanes. Physical properties of alkanes and cycloalkanes. Sources of alkanes. Reactivity of alkanes. Oxydation and combustion. Halogenation reaction. Homolytic cleavage. Radical species.

Chirality. Chiral and achiral molecules. Definition of stereocenters. Stereoisomers. R/S designation. Fischer projections. Enantiomers. Molecules having more than one chiral center: diastereomers and meso compounds. Properties of stereoisomers. Optical activity. Racemic mixtures and their resolution. Enantiomeric and diastereomeric excess. Chirality in the biological world. Enantiomers in biology and drugs. Origin of chiral homogeinity in nature.

Alkenes and alkynes. Structure and nomenclature. Geometric isomerism (cis/trans and E/Z). Cycloalkenes. Terpenes. Alkenes reactions. Electrophile addition to the double bonds and polymerization reactions. Addition of halogenidric acids. Carbocation stability. Alkene hydration. Chlorine and bromine addition to alkenes: the bromonium ion. Stereoselective and stereospecific reactions. Glycols formation. Reduction of alkenes: heats of hydrogenation and stability of alkenes. Stereochemistry in the addition reactions to alkenes. Structure and acidity of alkynes. Isolated, conjugated and cumulated dienes. Heats of hydrogenation. Polymerization of alkenes and dienes.

Halogenoalkanes: structure and nomenclature. Nucleophilic aliphatic substitution. Nucleophiles and bases, electrophiles and acids. SN2 and SN1 mechanisms: differences in the kinetics, in the mechanism and in the stereochemistry of the products. Stereoselectivity and stereospecificity of the reactions. Factors influencing the rates of SN2 and SN1 reactions: structure of the nucleophile, of the RX, of the leaving group and of the solvent. Examples of SN2 and SN1 reactions. Beta-elimination and dehydroalogenation reactions. Saitzev’s rule, E2 and E1 mechanisms. E2 vs E1. Stereochemistry of E2 reactions. Biosynthesis of terpenes.

Alcohols, ethers and thiols: structure, nomenclature and physical properties. Acidity of the alcohols according to the inductive effects of substituents. Acidity of methanol, ethanol, iso-propanol and terz-butanol. Reaction with active metals, conversion into halogenoalkanes. Mechanism of the reaction of alcohols and thionyl chlorids. De-hydration reaction in acidic catalysis. Oxydation of 1° and 2° alcohols. Ether bond formation via Williamson reaction. Crown ether and cryptands. Epoxydes. Reaction of thiols: acid-base and oxydation reactions.

Benzenes and their derivatives. Resonance energy and aromaticity. Heterocyclic aromatic compounds and the nucleic acid bases. Nomenclature. Mono- di- and poly-substituted benzenes. Phenols: acidity and acid base reactions. Introduction to the Aromatic Electrophilic Reaction. Acidity of substituted phenols. Separation of phenols from alcohols and of acids from phenols.

Amines. Classification of the amines. pKb and pKa of amines. Henderson-Hasselbach equation. Structure-basicity relationship in aliphatic, aromatic and heterocyclic aromatic amines. Reactions with acids. Stereochemistry at the nitrogen atoms of amines and quaternary ammonium salts..

Ketones and aldehydes. Structural characteristics of the carbonyl group. Nomenclature. Reactions of the cabonyl group. Addition of oxygen nucleophiles: emiacetals and acetals. Addition of nitrogen nucleophiles: the imines or Schiff bases. Keto-enolic tautomerism and racemization of a carbon atom alfa to the carbonyl group. Oxydation and reduction of aldehydes and ketones.

Carboxylic acids: structure and nomenclature. Physical properties. Acidity and effects of the substituents in acetic and benzoic acids. Separation alcohols/phenols/carboxylic acids. Reduction of carboxylic acids. Esterification of Fischer. Conversion into acyl chlorides. Decarboxylation of beta-ketoacids and malonic acids.

Derivatives of carboxylic acids: acyl chlorides, anhydrides, esters and amides. Structure and nomenclature. Lactons, lactams and phosphoric acid esters. Nucleophilic acyl substitution: similarity and differences with the reactivity of the carbonyl groups f aldehydes and ketones. Differences in reactivity of the derivatives of carboxylic acids on the type of leaving group and of the electrophilicity of carboxy group. Hydrolysis, reaction with alcohols, ammonia and ammines. Reduction of esters and amides.

Enolate anions. Acidity of the H atoms in alfa position to a carbonyl group. Formation of enaolates. Enolizable ketones and aldehydes. Formation of enols by acidic catalysis. Aldol condensation: mechanism of the reaction under basic or acidic catalysis. Symmetric and crossed aldol condensations. Intramolecular aldol condensations. Aldol condensation in the biological world.

Biological important molecules
Carbohydrates: classification. D- and L-monosaccharides: Fischer representations. Aminosugars. Emiacetalic cyclic structure: Haworth projection and chair conformation. Epimers and anomers. Mutarotation. Monosaccharide reactions: glucoside formation, reduction of alditols, oxydation of aldonic acids, glucose test. Ascorbic acid. Disaccharides: Maltose, Lactose, Saccharose. Blood group substances. Polysaccharides: starch, glycogen and cellulose.

Amino acids. Classification. Natural alfa-amino acid. Acid-base properties. Isoelectric point. Polypeptide and proteins: primary, secondary (alfa helix and beta-sheets), tertiary and quaternary structures. Chemical synthesis of polypeptides. Solid-phase synthesis. Biosynthesis of proteins.

Lipids: classification. Triglycerids: saturated and unsaturated fatty acids. Oils and fats. Soaps and detergents. Phospholipids: lipidic double layer and mosaic model of the cell membranes. Liposoluble vitamines. Steroids: cholesterol, steroid hormons, bile acids. Cholesterol biosynthesis. Prostaglandines.

Nucleic acids. Nitrogenous bases, nucleosides, nucleotides. DNA: primary, secondary structures. RNA.

Bibliography

Autore/i: Bettelheim - Brown - Campbell - Farrell | Editore: Edises
ISBN: 9788879595421 | Volume: Unico
Edizione: 2011 | Finitura: Brossura
Pagine: 912
To be consulted
· N. L. Allinger, M. P. Cava, D. C. De Jongh, C. R. Johnson, N. A. Lebel, C. L.
Stevens, Chimica Organica, 2^ Edizione, Zanichelli, Bologna.
· W. H. Brown, C. S. Foote: Chimica Organica, 2^ Edizione, EdiSES, Napoli.
· J. McMurry, Chimica Organica, 1^ Edizione, Zanichelli, Bologna.

Teaching methods

Oral lectures and practice on organic chemistry problems

Assessment methods and criteria

Written and oral exam.

Other information

Theoretical explanations (7 hours/week during 6 weeks) together with tutoral
activity (1-2 hours/week) consisting in exercises solved in classroom by the students
and aimed at applying and reinforce the concepts learned.
The examination consists of a written and an oral proof.

ORGANIC CHEMISTRY cod. 14786