Organic Chemistry — DU B.Sc. (Prog.) Applied Life Sciences with Agrochemicals and Pest Management pertaining to Chemistry Previous Year Question Papers

(c) Giving an example, explain the limitations of Williamson's ether synthesis. (5x3=15) Science with Agro Chemicals & Pest 1. (a) Assign the priority and designate R- / S- to the following: (i) What is hyperconjugation? What are its important consequences? (ii) Explain the Substitution reactions with one example each. Substitution reaction (iii) What is carbocation? Explain the stability of primary, secondary, and tertiary carbocations. (c) (i) What is hyperconjugation? How will you explain stability of methylated alkenes based on hyperconjugation? (ii) Hydroboration-oxidation reaction 5. (a) Carry out the following conversion: (Any two) (i) Propene to Propan-l-ol (iii) Pent-2-ene to Pentane (b) (i) Arrange the following carboxylic acids in increasing order of their acidic strength and justify your answer. (ii) Arrange the compounds of each set in order of reactivity towards SN2 displacement : (i) Explain the mechanism of S 2 reaction with a suitable example. (b) Giving reason, write the major product formed in ! the following reactions. (c) Explain and write the following reaction with a suitable example (i) Cope Elimination (ii) Identify Electrophile and Nucleophiles (a) Define conformations. Write all possible conformations of n-butane. Arrange them in increasing order of stability, with explanation. (b) (i) Assigning the priority order, explain how will you designate E-IZ nomenclature in the following: (i) Which of the two: trans-but-2-ene-or trans-pent-2-ene is more non polar? (c) Identify Aromatic and non-aromatic and explain the reason. 3. (a) Explain the reaction (Any two (i) Nitration of Bromobenzene with mechanism (ii) Friedel Craft Acylation of Benzene with (iii) Explain Electrophilic Aromatic Substitution with one example (b) Convert the below conformer to Fisher Projection (c) Explain Why (Any two) (i) Phenol is more acidic than Alkyl alcohol? (ii) Grignard reagents should be prepared under anhydrous conditions? (iii) Alkyl halides, though polar, are immiscible with water? (5x3=15) 4. (a) (i) Arrange the following amines in the increasing order of their basicity and justify your answer.