91Ó°ÊÓ

Classify the following as 'chiral' and 'achiral'. (a) Scissors (b) Shoe (c) Hammer (d) Nail (e) Screw (f) T-shirt (g) Foot (h) Fork (i) Nose

In the following compounds, indicate the stereogenic (or chiral) centre by putting an asterisk mark over it. (a) \(\mathrm{CH}_{3} \mathrm{CH}(\mathrm{Br}) \mathrm{CH}_{2} \mathrm{OH}\) (c) \(\mathrm{CH}_{3} \mathrm{CH}(\mathrm{Cl}) \mathrm{CH}(\mathrm{Br}) \mathrm{CH}_{3}\) (b) \(\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{CH}(\mathrm{OH}) \mathrm{CH}_{3}\) (d) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}(\mathrm{Cl}) \mathrm{CH}\left(\mathrm{CH}_{3}\right) \mathrm{CH}_{3}\)

What are stereoisomers?

Define the terms enantiomers and diastereomers.

Comment on the physical and chemical properties of enantiomers and diastereomers.

What is optical activity? What is the necessary condition for a molecule to be optically active?

What are meso compounds? Are the meso compounds optically active on inactive? Explain your answer through a suitable example.

What is general formula for determining the number of stereoisomers possible for a given compound? Indicate the number of stereoisomers possible for each of the following: (a) \(\mathrm{CH}_{3} \mathrm{CH}\left(\mathrm{NH}_{2}\right) \mathrm{COOH}\) (b) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}(\mathrm{OH}) \mathrm{CH}_{2} \mathrm{CH}_{3}\) (c) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}(\mathrm{Br}) \mathrm{CH}(\mathrm{Cl}) \mathrm{CH}_{3}\) (d) CHOCH(OH)CH(OH)CH(OH)CH \(_{2} \mathrm{OH}\)

Draw the Fischer projections for all possible stereoisomers of: (a) \(\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{CH}\left(\mathrm{NH}_{2}\right) \mathrm{COOH}\) (b) \(\mathrm{HOOCCH}\left(\mathrm{CH}_{3}\right) \mathrm{CH}\left(\mathrm{CH}_{3}\right) \mathrm{CH}_{2} \mathrm{OH}\)

Draw the Newman projection for different conformations possible for butane. Give the conformational analysis for butane.