Learning outcomes of the course unit
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 contents summary
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.
Course contents
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. Hyperconjugation. Orientation in
h a l o g e n a t i o n r e a c t i o n s . S t a t i s t i c a l a n d r e a c t i v i t y f a c t o r s .
Reactivity/selectivity in organic reactions. Regiochemsitry in radical
reactions. Exercises.
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 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. Reactivity of alkynes. Addition of H2, X2, HX e H2O.
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. Betaelimination
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 int
Recommended readings
Main textbook
· W. Brown, T. Poon: Introduzione alla Chimica Organica, 3^ Edizione,
EdiSES,
Napoli.
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.
At the half and at the end of the semester, it is possible to attend two
intermediate
written proofs regarding the first and second part of the programme,
respectively.
Who will pass both the intermediate proofs can directly access the oral
examination.
Other informations
Theoretical explanations (4 hours/week during 13 weeks) together with
tutoral
activity (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.
At the half and at the end of the semester, it is possible to attend two
intermediate
written proofs regarding the first and second part of the programme,
respectively.
Who will pass both the intermediate proofs can directly access the oral
examination.
