ORGANIC CHEMISTRY I

MODULE 1 (n CREDITS. 1.4)

 

PRINCIPLE OF CHEMICAL BASE

Electronic configurations of elements and the Octet rule. Electron spin, Pauli exclusion principle and principle of maximum multiplicity.

Chemical bonds: ionic and covalent (homopolar, polar, and dative). Bond Polarity and polarized molecules. Force and energy to bond.

Length and bond angle. Formal charge and Oxidation number of atoms in organic compounds. Atomic and molecular orbitals. HOMO and LUMO orbitals. Hybrid orbitals sp³, sp², and sp. σ e л bonds.

Molecular interactions: inter-and intramolecular forces: dipole-dipole interactions, dipole-induced dipole, hydrogen bonds and van der Waals forces. Physical relief of organic molecules: melting and boiling points, solubility.

Definition of resonance and rules for writing correct resonance structures of organic molecules. Inductive and mesomeric effects.

Definition of acid and base according to the theories of Arrhenius, Bronsted-Lowry and Lewis.

Scale of acidity and basicity.

 

FUNCTIONAL GROUPS, CLASSES OF ORGANIC COMPOUNDS AND NOMENCLATURE

Description of the functional groups. Classes of organic compounds. Nomenclature and chemical-physical characteristics.

 

STUDY OF STEREOCHEMISTRY

Classification: constitutional isomerism and stereoisomerism. Diastereomers and enantiomers. Conformational differences (Newman projections) and configurations. Stereoisomerism and geometrical optics. Centers, stereogenic axes and planes.

Molecular chirality and ways to determine it (centers, axes and planes). Racemic and scalemic mixtures. Descriptors of cis / trans, E / Z, R / S configurations. Priority rules of Cahn-Ingold-Prelog. Representation of structures using Fischer projections (rules for their proper writing and manipulation). Pseudo-asymmetric centers (Descriptors of r / s configuration). Epimers. Properties scalar and pseudoscalar (optical activity, enantiomeric excess, optical purity). Relative configuration of asymmetric centers: Descriptors of D / L, erythro / threo, sin / anti, exo / endo configurations. Notes on the resolution of enantiomers.

REACTIONS OF ORGANIC CHEMISTRY.

Thermodynamic quantities involved in the reactions: changes in free energy, enthalpy and entropy, Gibbs equation. Energy diagrams that describe the variations of these quantities as a function of the reaction coordinate.

Kinetic variables involved in organic reactions: rate constants and activation energies. Reaction order. Relationship between the rate constants and equilibrium constant.

Cleavage of bonds by homolytic and heterolytic processes.

 

MODULE 2 (n CREDITS. 1.6)

 

HYDROCARBONS

Alkanes and Cycloalkanes:

Conformational analysis and voltage loop (heat of combustion).

Stereochemistry of cycloalkanes.

Synthesis of alkanes and cycloalkanes: hydrogenation of alkenes, reduction of alkyl halides, Synthesis of Corey-House.

Radical reactions: homolytic dissociation energy and enthalpy of reaction. Geometry and stability of alkyl radicals. Halogenation reactions of methane and higher alkanes: selectivity and Hammond-Leffler postulate.

 

Alkyl halides:

Reactions

Nucleophilic Substitution: SN1, SN2, and borderline mechanisms.

Neighboring-group participation

Elimination Reactions: E2, E1 and E1cb mechanisms.

Competition between substitution and elimination reactions.

Geometry and stability of carbocations and carbanions. Molecular transpositions.

Allylic halides and benzylic in nucleophilic substitution reactions.

Synthesis of alkyl halides ( see reactions of other functional groups)

 

Alkenes:

Reactions

Addition of: hydrogen halides, sulfuric acid, water, halogens (reaction mechanisms and stereochemistry). Stereospecific and stereo selective reactions: Formation of halohydrins. Ozonolysis. Hydroxylation. Oxidation and reduction (Heat of hydrogenation). Stability of alkenes.

Radical addition of hydrogen bromide. Allyl radical and allyl cation: description, stability and resonance. Allylic chlorination and bromination.

Preparation of Alkenes: dehydrohalogenation of alkyl halides, dehydration of alcohols, dehalogenation of vicinal dibromine, Wittig and related reactions, Julia olefination.

 

Alkynes

Acidity and replacement of the acetylenic hydrogen of terminal alkynes.

Reactions: Hydrogenation: Addition sin and anti. Addition of: halogens, hydrogen halides and water (keto-enol tautomerism). Oxidation reactions.

Preparation of Alkynes: dehydrohalogenation of alkyl dihalides. Reactions of metal acetylides with primary alkyl halides.

 

MODULE 3 (3 CREDITS)

 

Dienes and polyenes:

Conformations and stability. Addition 1.2 and 1.4 (kinetic versus thermodynamic control). Diels-Alder reaction.

 

Aromaticity and electrophilic aromatic substitution:

Structure and stability of benzene. Hückel's Rule: aromatic annulenes and ions. Aromatic compounds, antiaromatic and non-aromatics. Polycyclic aromatic compounds: naphthalene, anthracene, phenanthrene, pyrene and benzo [a] pyrene.

Electrophilic substitution reactions: halogenation, nitration, sulfonation, Friedel-Crafts alkylation and acylation. Substituents effects on the reactivity and orientation. Alkyl benzenes: Radicals and benzylic cations. Halogenation in the side chain and oxidation.

 

Alcohols:

Acid-base properties.

Reactions: with hydrohalic acids, with thionyl chloride, with methanesulfonyl chloride, with tosyl chloride, with trimethylsilyl chloride, with phosphorus tribromide. Dehydration. Synthesis of esters. Mitsunobu reaction. Oxidation reactions.

Preparation of alcohols: Hydration of alkenes, hydromercuration-demercuration, hydroboration-oxidation, nucleophilic substitution with hydroxyl, Grignard synthesis, hydrolysis of acid derivatives, reduction of: carbonyl compounds, acids and esters.

 

Ethers:

Reactions: acid cleavage. Claisen rearrangement.

Preparation: Intra-and Intermolecular Dehydration of alcohols. Alkoxymercuration-Demercuration. The Williamson ether synthesis.

 

Epoxides:

Reactions: Acid and base-catalyzed ring opening. Reaction with Organometallic compounds.

Preparation: Oxidation of alkenes with peroxy compounds. Dehydrohalogenation of halohydrins.

 

Diols:

Preparation: Hydroxylation of alkenes and epoxide ring opening: mechanistic and stereochemical aspects.

Reactions: oxidation with periodic acid. Formation of acetals and ketals.

 

Aryl and vinyl halides:

Reactions

Aromatic nucleophilic substitutions: addition-elimination, elimination-addition, Copper catalyzed reactions, and Vicarious.

Preparation: direct Halogenation. Reactions of aryldiazonium ions.

 

Phenols:

Reactions: Acid-base properties. Replacing the ring (Reimer and Tieman, Kolbe, nitrosation, and copulation reaction). Synthesis of esters. Claisen transposition. Synthesis of ethers.

Preparations: Cumene Synthesis. Dow process. Alkaline fusion of sulfonates; hydrolysis of aryldiazonium ions.

 

MODULE 4 (n CREDITS. 4)

Aldehydes and ketones (electrophilic and nucleophilic characteristics):

Reactions: Nucleophilic Addition to the carbonyl group. Addition of water to carbon-oxygen double bond, addition of alchols, addition of ammonia and its derivatives, addition of hydrocyanic acid, sodium bisulfite, ylides of phosphonium (Wittig reaction), addition of organometallic reagents (compounds of alkyl lithium, Grignard reagents, Reformatsky reagent): mechanistic and stereochemical aspects.

Reduction with hydrides or with hydrogen in the presence of metal catalysts. Clemmensen and Wolff-Kishner Reduction. Oxidation with potassium permanganate, silver oxide and peroxyacids (Baeyer-Villiger oxidation).

Cannizzaro reaction. Acidity of hydrogens α in the carbonyl group, keto-enol tautomerism, the carbonyl carbon with electrophilic character and ion enolate with nucleophile character. The formation of the enolate ion from asymmetric ketones: kinetic and thermodynamic control of their alkylation reaction. Racemization. Halogenation of ketones and aldehydes Aloformic reaction. Aldol condensation with bases and acids. Claisen-Schmidt reaction. Robinson annelation.

Synthesis of aldehydes: Oxidation of primary alcohols and aryl-methyl groups. Hydration of alkynes. Ozonolysis of alkenes. Controlled reduction of acid chlorides, esters and nitriles.

Synthesis of ketones: Oxidation of secondary alcohols. Ozonolysis of alkenes, Friedel-Crafts Acylation. Hydration of alkynes. Addition of lithium dialkylcuprate to acyl chlorides: Addition of organ lithium reagents or Grignard to nitriles.

 

Carboxylic acids and derivatives:

Reactions: Acidity (factors that influence the acidity of the carboxylic hydrogens and the acidity of the hydrogens in position α in the derivatives) and basicity (factors that influence the oxygen basicity of carbonyl derivatives). Nucleophilic substitution within the acyl carbon (mechanism and reactivity of acid derivatives). Hydrolysis reaction in acid and base. Hell-Volhard-Zelinsky reaction. Homologation of carboxylic acids.

Synthesis: primary alcohols oxidation results in aldehydes. Ozonolysis of alkenes and alkynes. Addition of organo-metallic compounds to carbon dioxide. Hydrolysis of acyl chlorides, anhydrides, esters, lactones, amides, lactams, and nitriles. Derivatives of carbonic acid. Decarboxylation.

Acyl halides:

Reactions: Rosemund and LiAlH4 reduction. Nucleophilic reactions with oxygen, nitrogen, sulfur and carbon.

Synthesis: carboxylic acids react with thionyl chloride, or with PX3 or with PX5.

Anhydrides:

Reactions: Reactions with nucleophilic oxygen, nitrogen, sulfur and carbon.

Synthesis: acyl halides and carboxylates. Dehydration of carboxylic acids.

Ester:

Reactions: Trans-esterification. Reduction with hydrides. Nucleophilic reactions with oxygen, nitrogen, sulfur and carbon. Claisen condensation.

Synthesis: Fischer reaction. Reaction of the acid with diazomethane. Acyl halides with alcohols or alcoholates.

Amides:

Reactions: Hoffman degradation. Trans-amination. Reduction with LiAlH4.

Synthesis: Pyrolysis of ammonium carboxylates, reaction of acyl halides or anhydrides or esters with ammonia or primary and secondary amines (Schotten-Baumann reaction). Partial hydrolysis of nitriles.

Nitriles:

Reactions: addition of alcohols to form imino ester, addition of amines to form amidines. Reduction with LiAlH4, with H2 in the presence Ni, with DIBAL-H

Acid and basic hydrolysis.

Synthesis: The substitution reaction of alkyl halides with cyanide. Dehydration of primary amides. Dehydration of oximes with acetic anhydride.

 

Aliphatic and aromatic amines:

Reactions: Acid-base properties. Factors influencing the basicity (solvation effects, electron delocalization of , hybridization state of nitrogen, mesomeric and inductive effects of substituents). Nucleophilic properties of nitrogen: alkylation, acylation, oxidation, nitrosation. Hofmann and Cope elimination. The Hinsberg test. Aromatic diazonium salts: preparation and reactions with and without nitrogen removal. Synthesis using the diazonium salts.

Synthesis: ammonolysis of halides, alkylation of imides (Gabriel synthesis); reduction of nitro compounds, amides and nitriles; reductive amination; Hofmann, Curtius and Schmidt transposition.

 

Reactions of nucleophiles carbon with carbonyl groups:

Aldol condensation. Imines and iminium ion condensation. Mannich reaction. Acylation of carbanions. Claisen condensation. Acetoacetic synthesis. Malonic synthesis. Dieckmann condensation. Reformatsky reaction. Stork Reaction.

 

Carbonyl compounds α, β-unsaturated:

Reactions: Nucleophilic addition of nitrogen, oxygen, and carbon (Addition of Michael). Normal and conjugate addition.

Synthesis: Knoevenagel, Perkin, , Stobbe, Baylis-Hilman reactions.

 

Organometallic compounds:

Preparation and properties of organolithium and organomagnesium compounds; Organo-zinc, -cadmium, -mercury compounds; Reactions involving organopalladium intermediates; organoboron compounds.

 

 

 

Books recommended: a) Organic Chemistry by Bruno Botta, Authors: hanger. Botta, Cacchi, Chiacchio, Corsaro, ... Taddei. Ed Edi-Ermes 2011 (Milan) ISBN 978-88-7051-327-1. b) W. H. Brown c) P. Y. Briuce d) K. And Peter C. Vollhardt, e) A. Streitwieser, C. H. Heathcock f) Norman and Coxon;

 

Prerequisites: General Chemistry

 

Evaluation procedure:

 

XX written test: The written test will be based on the nomenclature of simple organic compounds, on the acidity and basicity, on the synthesis of organic compounds in several stages and on the identification of some of the organic mechanisms studied during the course. To access the oral examination must have passed the written test

XX oral test: The oral test is based on the discussion of the written test and on the basic knowledge . and basic understanding of the functional groups studied during the course of study