This class is a possible elective for students on Maths-based degrees, as it does not conflict with compulsory Mathematics/STAMS classes.
Details are given in good faith, but this class and its code or timetable may be subject to change or cancellation.
For further information on this class please contact The Department of Pure and Applied Chemistry (external link)
This class is an additional elective available in second/third year.
Core Details
| Semester | 2 |
|---|---|
| Credits | 10 |
Essential Prerequisites
Description
Revision of concepts of substitution, addition, elimination. Homolytic substitution. Substitution of alkanes, and of benzylic and allylic systems. Relative reactivity of CH3, CH2, CH, i.e. selectivity of substitution. Radical substitutions using alternative processes (e.g. tributyltin hydride) and autoxidation. Nucleophilic substitution. Brief revision of SN1 / SN2 mechanisms and stereochemical consequences. Substitution of halides and esters including sulfonates.
Preparative aspects: synthesis of amines (NH3 and Gabriel) and ethers, alkylation of acetylenes, malonate and acetoacetate with explanation of the role of acidic hydrogen atoms. Tautomerism, Resonance and Aromaticity.
The concepts: definitions and criteria. Keto-enol tautomerism in simple ketones, acetoacetate and 1,3-diketones. Resonance of enolate and carboxylate ions and of benzene. Requirements for aromaticity. Electrophilic substitution ofarenes. Strategic synthetic concepts using activating and deactivating groups and their directive effects for 2nd and 3rd substitutions. Functional group modification, especially diazotisation; uses of diazonium salts in synthesis.
Free Radical Addition: Radical addition to carbon-carbon double bonds ("anti-Markovnikov" addition). Polymerisation reactions. Addition to C-C Multiple Bond Brief revision of electrophilic addition to carbon-carbon double bonds. Hydroboration reactions showing "anti-Markovnikov" products and evidence for syn-addition. 1,2- and 1,4- addition to conjugated dienes.
Nucleophilic additions: Nucleophilic addition to carbonyl groups, nitriles, etc. Examples include organometallic reagents and hydride type reducing reagents. Addition of ROH, HCN and H2N-X. Aldol, Claisen and Dieckmann condensations, Michael addition, and Wittig reaction. Reduction of aldehydes and ketones by Clemmensen and Wolff-Kishner procedures, and via thioketals. Esterification and amide formation (addition/elimination processes), imine and enamine formation, and reductive amination.
Additions Involving Cyclic Intermediates and Cvcloadditions: Ozonolysis and hydroxylation (KMn04 and OsO4) of alkenes, cleavage of vic-diols (H5IO6 and Pb(OAc)4) and epoxidation of alkenes. Addition of carbenes to double bonds. Other additions of carbenes are outlined elsewhere, e.g. use of diazomethane in esterifications included in esterification section. Concerted additions (Diels-Alder and catalytic hydrogenation).
Rearrangement Reactions: Revision of simple carbocation rearrangements, especially illustrated by the pinacol rearrangement. Brief overview of some other important rearrangement reactions.
Elimination Reactions: Brief revision of E1 and E2 mechanisms. Zaitsev and Hofmann rules. Hofmann elimination Elimination by concerted ("cyclic") mechanism, e.g. Cope elimination. Oxidation of alcohols involving E2 mechanism.
Timetable
Tue, Thu 11