Module Details

The information contained in this module specification was correct at the time of publication but may be subject to change, either during the session because of unforeseen circumstances, or following review of the module at the end of the session. Queries about the module should be directed to the member of staff with responsibility for the module.
Title Organic Chemistry II
Code CHEM231
Coordinator Dr RP Bonar-Law
Chemistry
R.P.Bonar-Law@liverpool.ac.uk
Year CATS Level Semester CATS Value
Session 2021-22 Level 5 FHEQ First Semester 15

Pre-requisites before taking this module (or general academic requirements):

CHEM130 CHEM130 Introductory Organic Chemistry 

Aims

The aim of this module is to introduce important carbon-carbon bond forming reactions within a mechanistic and synthetic framework, together with exposure to a selection of stereochemical issues.


Learning Outcomes

(LO1) Students will be able to solve problems featuring:
* Scope and mechanisms of basic reactions (nucleophilic and electrophilic substitutions, addition and elimination reactions).
* Basic carbonyl chemistry (alkylation, acylation, aldol, conjugate additions).
* Structure, reactivity and synthesis of simple heterocycles (including pyridines, pyrroles, furans).
* Functional group interconversions and stereochemistry.


Teaching and Learning Strategies

This module consists of 33 50-minute lectures, plus several revision lectures at the end of the course. The material presented at the lectures is supported by five 1-hour tutorials, given fortnightly.
Lectureas and tutorials online in 2020-21.


Syllabus

 

The Chapters below refer to "Organic Chemistry" by Clayden et al

Carbanion chemistry
* Acids, bases, enolate anions and other stabilised carbanions: pKas of common acids. Choosing a base for carbon acids. Reversible and irreversible formation of enolates. (Ch 8,20)
* Alkylation of enolate ions and other carbanions: Definition, alkylating agents. Direct alkylation with LDA. Alkylation of 1,3-dicarbonyls, hydrolysis and decarboxylation. Use of enamines and silyl enol ethers. (Ch 25)
* Acylation of carbanions: Definition, acylating agents. Acylation of ketones with formate and carbonate esters. Acylation of esters with esters, Claisen condensation and Dieckmann cyclisation. Acylation of enamines and possibly silyl enol ethers. Acylation using LDA. (Ch 26)
* Reactions of enolates with aldehydes and ketones: Aldol and related reactions: Self-aldol reactions, equilibria with aldehydes and ketones. Mixed aldols. Mixed aldols with 1,3-dicarbonyls, Knoe venagel reaction. Intramolecular aldol. Lithium and zinc enolates in aldol reactions, Reformatsky reaction. (Ch 26)
* Alkenes: the Wittig reaction and related methods: Wittig mechanism, stabilised and unstabilised ylides, stereochemistry. Horner-Wadsworth-Emmons reaction. Alkenes by dehydration of alcohols. (Ch 27)

Conjugate additions
* Conjugate addition reactions of activated alkenes. Selectivity of addition of organometallics and use of organocuprates. (Ch 22)
* Sequential reactions (Robinson annelation and dimedone synthesis) as routes to 6-membered rings. (Ch 26)

Chemoselectivity
* Synthetically useful reductions including metal hydride reagents, catalytic hydrogenation, and deoxygenation of carbonyl groups. (Ch 23)
* Synthetically useful oxidations including chromium (VI) based reagents, Swern and other DMSO systems, Baeyer-Villiger and other per-acid oxidations. (Ch 23)

Introduction to aromatic heterocyclic chemistry (ch. 29, 30)
* Pyr idine: Introduction to aromatic heterocyclic chemistry. Electrophilic aromatic substitution of hydrogen. Nucleophilic aromatic substitution of hydrogen, Chichibabin reaction. Nucleophilic additions.
* Substituted pyridines: Nucleophilic aromatic substitution of halopyridines. Reactivity of methylpyridines. Hydroxypyridines and aminopyridines. Pyridine N-oxides. Diazines; nucleophilic and electrophilic substitutions.
* Quinolines, isoquinolines and diazines: Quinoline and isoquinoline as benzopyridines, electrophilic and addition reactions. 2. Diazines; nucleophilic and electrophilic substitutions.
* Pyrrole and Indole: Introduction to five-membered aromatic rings. pK a s of pyrrole, electrophilic substitution, regiochemistry, Vilsmeier-Haack and other reactions. Indole as benzopyrrole, electrophilic substitution, regiochemistry, Mannich reaction.
* Furans and thiophenes: Furans; electrophilic and addition reactions, lithiation, other reactions. Thiophenes, reactions, d esulfurisation.
* Synthesis of five and six membered aromatic heterocycles: Introduction 1. Pyridines; summary of approaches, mechanism of Hantzsch synthesis, modifications, other methods. 2. Pyrimidines; common reagent combinations and mechanisms. 3. Pyrroles, furans, thiophenes; from 1,4-diketones, mechanism of Knorr pyrrole synthesis. 4. Imidazoles, pyrazoles and isoxazoles; from 1,3-dicarbonyls and hydrazine or hydroxylamine, 1,3-dipolar cycloadditions.

Stereochemistry and reactions
* Stereochemistry of compounds containing one stereogenic carbon centre including R and S. Stereochemistry of compounds containing more than one stereogenic carbon centre (enantiomers and diastereoisomers). Stereochemistry of chiral compounds not possessing a stereogenic centre (allenes, biphenyls). (Ch 14)
* Nucleophilic substitution at saturated carbon, S N 2 - mechanism, kinetics (including revision of basic concepts), stereochemistry, nucleophile, leaving group, structure of substrate, solvent. Synthetic applications. (Ch 15)
* Elimination reactions - mechanism and stereoselectivity. E1, E2, E1cB Stereospecific and regioselective E2 elininations. (Ch 17)
* Electrophilic addition to alkenes - stereo- and regioselectivity. Bromination, epoxidation, iodolactonisation. Synthetic applications. (Ch 20)
* Nucleophilic Substitution at Carbonyls. Tetrahedral intermediates. Common mechanisms of ester hydrolysis. (Ch 10)
* Stereochemistry and face selectivity concerning reactions at sp2 hybridized carbon centres. (Ch 33,34)


Recommended Texts

Reading lists are managed at readinglists.liverpool.ac.uk. Click here to access the reading lists for this module.

Teaching Schedule

  Lectures Seminars Tutorials Lab Practicals Fieldwork Placement Other TOTAL
Study Hours 33

  5

      38
Timetable (if known)              
Private Study 112
TOTAL HOURS 150

Assessment

EXAM Duration Timing
(Semester)
% of
final
mark
Resit/resubmission
opportunity
Penalty for late
submission
Notes
online class test. time-on task 1.5 hours      30       
online class test. 1.5 hours on task      40       
CONTINUOUS Duration Timing
(Semester)
% of
final
mark
Resit/resubmission
opportunity
Penalty for late
submission
Notes
Three online assignments      30