Description
Tutor Marked Assignment
Stereochemistry and Reactive Intermediates (MCH-012)
Course Code: MCH-012
Assignment Code: MCH-012/TMA/2025
Maximum Marks: 100
Note: Attempt all the questions. The marks for each question are indicated against it.
1. Carry out the following conversions as indicated.
a) Fischer form to: i) Staggered and Eclipsed Sawhorse forms and
ii) Staggered and Eclipsed Newman forms
(5)
COOH
COOH
OH H
OH H
b) Flying wedge form to Fischer forms
H OH
HO CH2CH3
i) C
H
Ph
ii) C
OH
COOH
(5)
2. a) Suppose that there is a mixture having a specific rotation of +75o and an
enantiomeric excess of 60%. Find out the enantiomeric composition of the
mixture.
(5)
b) Draw the meso isomers of the following compounds.
CH3
H3
C
Br OH
HO Br
OH
Cl
i) ii)
HO
Cl
(5)
3. a) List the properties of diastereomers. Indicate whether the following are
enantiomers or diastereomers.
and
H
Cl
HO
H3C
Cl
OH
CH3
H
H
Br
H
Br
OH
OH
and
OH
OH i) ii)
(5)
b) How are disubstituted cyclohexanes different from monosubstituted
cyclohexanes with reference to the isomerism? Draw the two chair
conformations for each of the following disubstituted cyclohexanes. Draw also
the cis and trans isomers and indicate the more stable isomer.
(5)
5
i)
cis-Bromo-1-methylcyclohexane
ii) trans-2-Butyl-1-isopropylcyclohexane
iii) cis-4-Ethyl-1-hydroxycyclohexane
4. a) What are the advantages and limitations of method of quasi-racemates? (5)
b) What is pseudoasymmetry? Explain with the help of a suitable example. (5)
5. a) Briefly explain conformationally rigid systems and conformationally mobile
diostereomers giving one example for each. Also correlate the reactivity and the
conformations of these examples.
(5)
b) What are left- and right- circularly polarised lights? Draw suitable diagrams for
them.
Reviews
There are no reviews yet.