Syllabus (CHEMISTRY)

Course Type: MAJ-7

Semester: 5

Course Code: BCEMMAJ07C

Course Title: Organic Chemistry – III

(L-P-Tu): 4-2-0

Credit: 6

Practical/Theory: Combined

Course Objective: COURSE OBJECTIVE OF MAJOR - 7: The syllabus of Major -7 has been designed to provide the students with in-depth knowledge of addition reactions of alkenes and alkynes, including aromatic electrophilic and nucleophilic substitution reactions, various react

Learning Outcome: COURSE OUTCOMES OF MAJOR – 7: CO- 7.1 Thorough understanding of addition reactions involving alkenes and alkynes. CO- 7.2 Detailed study of various aromatic electrophilic and nucleophilic reactions . CO- 7.3 Detailed study of reactions involving carbony

THEORY:

CHEMISTRY OF ALEKENES & ALKYNES: (12 L)

1. Addition to C=C: mechanism (with evidence wherever applicable), reactivity, regioselectivity (Markownikoff and anti-Markownikoff additions) and stereoselectivity; reactions: hydrogenation, halogenations, iodolactonisation, hydrohalogenation, hydration, oxymercuration-demercuration, hydroborationoxidation,epoxidation, syn and anti-hydroxylation, ozonolysis, addition of singlet and triplet carbenes; electrophilic addition to diene (conjugated dienes and allene); radical addition: HBr addition; mechanism of allylic and benzylic bromination incompetition with brominations across C=C; use of NBS; Birch reduction of benzenoid aromatics; interconversion of E - and Z - alkenes; contra-thermodynamic isomerization of internal alkenes.

2. Addition to C≡C (in comparison to C=C): mechanism, reactivity, regioselectivity (Markownikoff and anti-Markownikoff addition) and stereoselectivity; reactions: hydrogenation, halogenations, hydrohalogenation, hydration, oxymercuration-demercuration, hydroboration-oxidation, dissolving metal reduction of alkynes (Birch); reactions of terminal alkynes by exploring its acidity; interconversion of terminal and non- terminal alkynes.

AROMATIC REACTIONS: (10 L)

1. Electrophilic aromatic substitution: mechanisms and evidences in favour of it; orientation and reactivity; reactions: nitration, nitrosation, sulfonation, halogenation,Friedel-Crafts reaction; one-carbon electrophiles (reactions: chloromethylation, Gatterman-Koch, Gatterman, Houben-Hoesch, Vilsmeyer-Haack, Reimer-Tiemann, Kolbe-Schmidt); Ipso substitituion.

2. Nucleophilic aromatic substitution: addition-elimination mechanism and evidences in favour of it; SN1 mechanism; cine substitution (benzyne mechanism), structure of benzyne.

Carbonyl and Related Compounds (30L)

1. Addition to C=O: structure, reactivity and preparation of carbonyl compounds; mechanism (with evidence), reactivity, equilibrium and kinetic control; Burgi-Dunitz trajectory in nucleophilic additions; formation of hydrates, cyanohydrins and bisulphite add nucleophilic addition-elimination reactions with alcohols, thiols and nitrogen- based nucleophiles; reactions: benzoin condensation, Cannizzaro and Tischenko reactions, reactions with ylides: Wittig and Corey-Chaykovsky reaction; Rupe rearrangement, oxidations and reductions: Clemmensen, Wolff-Kishner,LiAlH4, NaBH4, MPV, Oppenauer, Bouveault-Blanc, acyloin condensation;oxidation of alcohols with PDC and PCC; periodic acid and lead tetraacetateoxidation of 1,2-diols.

2. Exploitation of acidity of α-H of C=O: formation of enols and enolates; kineticand thermodynamic enolates; reactions (mechanism with evidence): halogenation ofcarbonyl compounds under acidic and basic conditions, Hell-Volhard-Zelinsky (H. V.Z.) reaction, nitrosation, SeO2 (Riley) oxidation; condensations (mechanism withevidence): Aldol, Tollens’, Knoevenagel, Claisen-Schmidt, Claisen ester includingDieckmann, Stobbe; Mannich reaction, Perkin reaction, Favorskii rearrangement;alkylation of active methylene compounds; preparation and synthetic applicationsof diethyl malonate and ethyl acetoacetate; specific enol equivalents (lithiumenolates, enamines, aza-enolates and silyl enol ethers) in connection with alkylation,acylation and aldol type reaction.

3. Elementary ideas of Green Chemistry: Twelve (12) principles of green chemistry;planning of green synthesis; common organic reactions and their counterparts:reactions: Aldol, Friedel-Crafts, Michael, Knoevenagel, Cannizzaro, benzoin condensation and Dieckmann condensation.

4. Nucleophilic addition to α,β-unsaturated carbonyl system: generalprinciple and mechanism (with evidence); direct and conjugate addition, addition of enolates (Michael reaction), Stetter reaction, Robinson annulation.

5. Substitution at sp2 carbon (C=O system): mechanism (with evidence): BAC2,AAC2, AAC1, AAL1 (in connection to acid and ester); acid derivatives: amides, anhydrides & acyl halides (formation and hydrolysis including comparison).

Organometallics: (8L)

Grignard reagent; Organolithiums; Gilman cuprates: preparation and reactions (mechanism with evidence); addition of Grignard and organolithium to carbonyl compounds; substitution on -COX; directed ortho metalation of arenes using organolithiums, conjugate addition by Gilman cuprates; Corey-House synthesis; abnormal behavior of Grignard reagents; comparison of reactivity among Grignard, organolithiums and organocopper reagents; Reformatsky reaction; Blaise reaction; concept of umpolung and base-nucleophile dichotomy in case of organometallic reagents.

READING REFERENCES:

1. Clayden, J., Greeves, N., Warren, S. Organic Chemistry, Second edition, Oxford University Press 2012.
2. Sykes, P. A guidebook to Mechanism in Organic Chemistry, Pearson Education, 2003.
3. Smith, J. G. Organic Chemistry, Tata McGraw-Hill Publishing Company Limited.
4. Carey, F. A., Guiliano, R. M. Organic Chemistry, Eighth edition, McGraw Hill Education, 2012.
5. Loudon, G. M. Organic Chemistry, Fourth edition, Oxford University Press, 2008.
6. Norman, R.O. C., Coxon, J. M. Principles of Organic Synthesis, Third Edition, Nelson Thornes, 2003.
7. Morrison, R. N. & Boyd, R. N. Organic Chemistry, Dorling Kindersley (India) Pvt. Ltd. (Pearson Education).
8. Finar, I. L. Organic Chemistry (Volume 1), Pearson Education.
9. Graham Solomons, T.W., Fryhle, C. B. Organic Chemistry, John Wiley & Sons, Inc.
10. March, J. Advanced Organic Chemistry, Fourth edition, Wiley.
11. Jenkins, P. R., Organometallic Reagents in Synthesis, Oxford Chemistry Primer, Oxford University Press.
12. Ward, R. S., Bifunctional Compounds, Oxford Chemistry Primer, Oxford University Press.

PRACTICALS:

Qualitative Analysis of Single Solid Organic Compounds

1. Detection of special elements (N, S, Cl, Br) by Lassaigne’s test.

2. Solubility and classification (solvents: H2O, 5% HCl, 5% NaOH and 5%NaHCO3).

3. Detection of the following functional groups by systematic chemical tests:

4. Aromatic amino (-NH₂), aromaticnitro (-NO₂), amido (-CONH₂, including imide),phenolic – OH, carboxylic acid (-COOH), carbonyl (-CHO and >C=O); only one testfor each functional group is to be reported.

5. Melting point of the given compound

6. Preparation, purification and melting point determination of a crystalline derivative of the given compound.

7. Identification of the compound through literature survey.

Each student, during laboratory session, is required to carry out qualitative chemical tests for all the special elements and the functional groups with relevant derivatization in known and unknown (at least six) organic compounds.

REFERENCES FOR PRACTICALS:

1. Vogel, A. I. Elementary Practical Organic Chemistry, Part 2: Qualitative Organic Analysis, CBS Publishers and Distributors.
2. University Hand Book of Undergraduate Chemistry Experiments, edited by Mukherjee, G.N. University of Calcutta, 2003.
3. Mann, F.G. & Saunders, B.C. Practical Organic Chemistry, Pearson Education (2009).
4. Furniss, B.S., Hannaford, A.J., Smith, P.W.G., Tatchell, A.R. Practical Organic Chemistry, 5th Ed.,Pearson (2012).

5. Clarke, H. T., A Handbook of Organic Analysis (Qualitative and Quantitative), Fourth Edition, CBS Publishers and Distributors (2007).