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
Year CATS Level Semester CATS Value
Session 2008-09 Level Two First Semester 15

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

Students should be able to solve problems featuring:

Scope and mechanisms of basic reactions (nucleophilic and electrophilic substitutions, addition and elimination reactions)

Some of the major synthetic pathways including carbonyl chemistry (alkylation, acylation, aldol, conjugate additions) and cycloadditions (Diels Alder, 1,3-dipolar additions)

Structure and reactivity of simple heterocycles (pyridines, pyrroles, furans)

Functional group interconversions and stereochemistry.


Syllabus
0 

Topic

Chapter(s) in "Organic Chemistry" Clayden et al

Carbanion chemistry (8 lectures)

 

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 8,21

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 26

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 28

Reactions of enolates with aldehydes and ketones: Aldol and related reactions.

S elf-aldol reactions, equilibria with aldehydes and ketones. Mixed aldols. Mixed aldols with 1,3-dicarbonyls, Knoevenagel reaction. Intramolecular aldol. Lithium and zinc enolates in aldol reactions, Reformatsky reaction.

Ch 27

Alkenes: the Wittig reaction and related methods

Wittig mechanism, stabilised and unstabilised ylids, stereochemistry. Horner-Wadsworth-Emmons reaction. Alkenes by dehydration of alcohols

Ch 31

Conjugate additions and cycloaddition (6 lectures)

 

Conjugate addition reactions of activated alkenes. Selectivity of addition of organometallics and use of organocuprates.

Ch 10, 23

Sequential reactions (Robinson annelation and dimedone synthesis) as routes to 6-membered rings.

Ch 29

The Diels-Alder reaction: stereospecificity, stereoselectivity and mechanism. The Diels-Alder reaction: determination of stereochemistry, regiochemistry, and scope.1,3-Dipolar cycloaddition reactions: scope, stereochemistry, and examples including diazomethane and ozone.

Ch 35

Chemoselectivity (4 lectures)

 

Dissolving metal reductions with metal-ammonia systems applied to aromatic systems (Birch reduction) and enones and their synthetic applications. Dissolving metal reductions applied to carbonyl groups - Pinacol coupling and acyloin condensation.

Ch 24, 26, 39

Synthetically useful reductions including metal hydride reagents, catalytic hydrogenation, and deoxygenation of carbonyl groups.

Ch 24

Synthetically useful oxidations including chromium (VI) based reagents, Swern and other DMSO systems, Baeyer-Villiger and other per-acid oxidations.

Ch 24

Introduction to aromatic heterocyclic chemistry (6 lectures)

 

Pyridine

Introduction to aromatic heterocyclic chemistry. Electrophilic aromatic substitution of hydrogen. Nucleophilic aromatic substitution of hydrogen, Chichibabin reaction. Nucleophilic additions.

Ch 43

Substituted pyridines

Nucleophilic aromatic substitution of halopyridines. Reactivity of methylpyridines. Hydroxypyridines and aminopyridines. Pyridine N-oxides. Diazines; nucleophilic and electrophilic substitutions.

Ch 43

Pyrrole and Indole 

Introduction to five-membered aromatic rings. pKas of pyrrole, electrophilic substitution, regiochemistry, Vilsmeier-Haack and other reactions. Indole as benzopyrrole, electrophilic substitution, regiochemistry, Mannich reaction.

Ch 43

Furans and thiophenes

Furans; electrophilic and addition reactions, lithiation, other reactions. Thiophenes, reactions, desulfurisation.

Ch 43

Stereochemistry and reactions (8 lectures)

 

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 16

Nucleophilic substitution at saturated carbon, SN2 - mechanism, kinetics (including revision of basic concepts), stereochemistry, nucleophile, leaving group, structure of substrate, solvent. Synthetic applications.

Ch17

Nucleophilic substitution at saturated carbon, SN1- mechanism, kinetics, structure of substrate, solvent, nucleophile, leaving group, stereochemistry and ion pairs. Synthetic applications.

Ch17

Elimination reactions - mechanism and stereoselectivity. E1, E2, E1cB Stereospecific and regioselective E2 elininations

Ch 19

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, BAc2, AAc2.

Ch 12,13

Stereochemistry and face selectivity concerning reactions at sp2 hybridized carbon centres.

Ch 33, 34


Teaching and Learning Strategies

This module consists of 33 50-minute lectures.The material presented at the lectures is supported by five 1-hour tutorials(10 % of final mark) given fortnightly at times to be published.  Four sets of assignments (10 % of final mark), similar to to tutorial problems, will be provided on alternate weeks;any problems arising from these will be dealt with in tutorials. Students should expect to spend at least six hours per week in private study related to module.


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

   5

       38
Timetable (if known) Mon 11-12, Tues 9-10, Fri 12-1
  		           
Private Study 112
TOTAL HOURS 150

Assessment
EXAM Duration Timing
(Semester)		 % of
final
mark		 Resit/resubmission
opportunity		 Penalty for late
submission		 Notes
Written Examination  3 hours  first  80  August     
CONTINUOUS Duration Timing
(Semester)		 % of
final
mark		 Resit/resubmission
opportunity		 Penalty for late
submission		 Notes
Continuous Assessment  11 weeks  first  20  no  Standard University Policy applies - see Department/School handbook for details.  This work is not marked anonymously  

Recommended Texts

Organic Chemistry, J.Clayden, N. Greeves, S. Warren and P. Wothers, OUP, 2000

 Additional Reading:

“Organic Chemistry” Third Edition by K.P.C. Vollhardt and N.E.Schore (Freeman, New York)

“Guide to Stereochemistry”, S.R. Buxton and S. M. Roberts, Addison-Wesley Longman, Harlow, 1996.

“Aromatic Heterocyclic Chemistry” by D.T. Davies; Oxford Science Publications, 1992.

 Advanced Reading:

 “Advanced Organic Chemistry A and B”, 3rd Ed, F.Careyand R. Sundberg, Plenum;

“Advanced OrganicChemistry”, 4th Ed, J.March, Wiley;

“Principles of OrganicSynthesis”, 3rd Ed, R.O.C. Norman and J.M. Coxon, Blackie;

“Organic Synthesis”, M.B. Smith, McGraw-Hill.