CHEM1201: Basic Organic Chemistry

Course Organizer: Prof CM Marson

Lecturers: Prof CM Marson and Dr M W Powner

Normal prerequisite: CHEM1004

Units: 1/2

Course evaluation: 2011/2012 (doc)

Moodle page: http://moodle.ucl.ac.uk/course/view.php?id=9040

Aims

CHEMM1201 aims to provide a general understanding of organic chemistry and a knowledge of basic organic reactions. The structure, conformation and stereochemistry of organic compounds, as well as their reactions will be studied. A basic  understanding of the fundamental principles of organic chemistry and the synthesis and reactivity of the most important functional groups in organic compounds will be developed.

Objectives

To understand and use:

  • Concepts of constitution, configuration and conformation.
  • Curved/curly arrows to show electron flow and hence provide all basic mechanisms.
  • Energy profiles.
  • Molecular orbital alignment in basic chemical reactions.
  • The structure and chemistry of alkanes, alkynes, alkynes, alkyl halides, alcohols, ethers and epoxides, aldehydes and ketones, carboxylic acids and their derivatives, simple compounds containing nitrogen.
  • Reactions in sequence to provide syntheses of simple organic compounds.

Course Structure

  • Lectures: 27
  • Tutorials: 9
  • Labs: 10 x 5 hours

Assessment

  • Exam: 75% (2 hours)
  • Lab: 15%
  • Coursework: 10%

Practical course organizer:

Dr M Porter

Recommended Texts

All titled "Organic Chemistry"

  • J Clayden, N Greeves, and S Warren 2012, Oxford University Press.
  • J E McMurry, 2012, Wadsworth.
  • F A Carey and R. M. Giuliano, 8th ed, McGraw-Hill, New York.
  • G M Loudon, 5th ed, 2009, Prentice Hall.

    Some less recent editions of these books are likely to be quite satisfactory


Course Outline

Fundamental concepts of organic chemistry (lectures 1 and 2, CMM)

Importance of organic chemistry.
Brief overview of organic infrared spectroscopy.
Functional groups as the building blocks of organic chemistry.
Electronegativity; polarity as guide to reactivity.
Relative acidity of functional groups: inductive and mesomeric stabilisation of the anion.
Nucleophilicity.
Showing the making and breaking of bonds using curved arrows 

General patterns of reactivity.
Oxidation levels of functional groups.
Correlation of oxidation levels with reagents and products.
How to analyse organic reactions.

Alkanes (lectures 3-5, MWP)
Structure and bonding: tetrahedral nature of sp3 carbon.
Conformational analysis: conformers, torsional angles, 1,3-interactions, energy diagrams, 3D projections.
Rings: strain and puckering. Depicting and analysing the cyclohexane ring: conformers, ring flipping and 1,4-interactions.
Carbocation formation and stability: superacids and hyperconjugation.
Halogenation: chain reactions, propagation cycles, enthalpy-driven selectivity and the Hammond postulate.

Alkenes (lectures 6-9, MWP)
Structure and bonding: trigonal nature of sp2 carbon, pi-bonds, (E)- and (Z)-isomers.
EA electrophilic addition: recapitulation of hyperconjugation, three-membered rings.
Rearrangements: migration of carbon, migration of hydrogen.
Hydroboration: anti-Markovnikov addition of B-H.
Oxidation: OsO4 KMnO4, O3, NaIO4, m-CPBA.
Reduction: hydrogenation.

Alkynes (lectures 10 and 11, MWP)
Structure and bonding: digonal nature of sp carbon.
Electrophilic addition: Markovnikov and anti-Markovnikov additions, hydrohalogenation, hydration of alkynes.
Reduction: hydrogenation (Lindlar catalyst) and Li-NH3 reduction.
Acidity of terminal alkynes and their use as nucleophiles. Use of trimethylsilylacetylene.

Alkyl halides (lectures 12-16, MWP)
Structure and bonding: electronegativity and periodicity. Covalent bond polarization, leaving group ability.
Nucleophilic displacements: SN1 and SN2 kinetics, geometry of attack (crossover experiments), nucleophilcity and periodicity, synthesis of ethers and nitriles. Recapitulation of acetylide anions as nucleophiles; use of silver(I).
Eliminations: E1 and E2 kinetics, formation of (E)-alkenes by elimination of alkyl halides; use of hindered bases. Recap hHalogenation of alkenes.
Metal exchange: alkyllithiums and Grignard reagents (sp3) and, vinyllithiums (sp2) and r. Recapitulation of alkynyllithiums (sp).

Preparation of alcohols (lecture 17, CMM)
Structure and physical properties of alcohols.
Preparation of alcohols: reduction of carbonyl compounds (H2 and Pd-C, NaBH4, LiAlH4);
Addition of Grignard reagents to carbonyl compounds; hydroboration-oxidation of alkenes;
oxymercuration of alkenes.

Reactions of alcohols (lecture 18, CMM)
Depicting stereochemical reactions (in general): inversion and retention.
Reactions at the alcohol oxygen atom: deprotonation, O-alkylation, O-acylation, O-sulfonylation.
Displacements at the alcohol carbon atom: conversion into alkyl chlorides and alkyl bromides.
Eliminations with dehydration: H2SO4; POCl3+pyridine; t-BuOK on the tosylate.
Eliminations across the C-O bond: Cr(VI) oxidations; sodium periodate cleavage of 1,2-diols.

Ethers and epoxidess (lecture 19, CMM)
Structure, preparation and reaction of ethers.
Structure and preparation of epoxides.
Reactions of epoxides with LiAlH4 and with C-, O-, N- and S-nucleophiles.

Structure and preparation of aldehydes and ketones (lecture 20, CMM)
Structure and reactivity of aldehydes and ketones.
Preparation of aldehydes and ketones by:
hydration of alkynes (for ketones);
oxidation of alcohols;
ozonolysis of alkenes;
Friedel-Crafts acylation. Concept of control in reactions.

Reactions of aldehydes and ketones (lectures 21-23, CMM)
Reactions of aldehydes and ketones with:
Reducing agents: (see lecture 15);
C-nucleophiles: HCN+KCN; Grignard reagents (see also lecture 15) and the concept of retrosynthesis as applied to alcohols; Wittig reaction.
O-nucleophiles: alcohols (giving acetals), m-CPBA (giving esters or lactones).
N-nucleophiles: amines (1° and 2°); amine+reducing agents (reductive amination giving an amine); hydrazine (giving hydrazones) and hydroxylamine (giving oximes).

C-Nucleophiles from aldehydes and ketones: generation and reactions of enols and enolates.
Bromination of ketones under acidic conditions (via enol).
Iodoform reaction (NaOH and I2,via enolate).
Aldol additions and aldol condensations (via enolate).

Preparation of nitrogen-containing compounds (lecture 24, CMM)
Compounds containing nitrogen.
Preparation of nitrogen-containing compounds by:
Reduction of existing N-functionality: nitro compounds, nitriles, amides, oximes;
Reductive amination of aldehydes and ketones;
Azide displacement of an alkyl halide followed by reduction of the azide (H2, Pd-C or LiAlH4).

Carboxylic acids and their derivatives (lectures 25 and 26, CMM)
Structures and reactivities of carboxylic acids and their derivatives.
Preparation of carboxylic acids by: oxidation of alcohols and aldehydes; hydrolysis of nitriles;
carboxylation of Grignard reagents.

Preparation and reactions of acid chlorides: preparation of esters, anhydrides, amides and ketones from acid chlorides.

Preparation of esters (from acids and acid chlorides).
Acid-catalysed and base-catalysed hydrolysis of esters.

Review of key principles; how to apply knowledge of organic chemistry (lecture 27, CMM)
Solving problems in organic synthesis.
Review of key methods for making C-C bonds:
Which carbanion to use? Cyanide and acetylide anions, Grignard reagents, Wittig reagents. Enol and enolates.
Which electrophile to use? Acid, mCPBA, halogen, alkyl halides, epoxides, ketones and aldehydes, carboxylic acid derivatives.
Using powerful reaction sequences: oxidation to aldehyde or ketone, then Grignard addition; Formation of Grignard reagent, then addition of CO2; Friedel-Crafts acylation then addition to the ketone.
Question-and-answer topics.