H3C)2HC "CH2CH

Q2. Answer any TWO of the following parts: (a) Draw the two main conformations that exist for cyclohexane. Explain clearly why one conformer is more stable than the other. Using cis-1-ethyl-3-methylcyclohexane, as an example, explain how ring flipping occurs. Draw both conformers of cis-1-ethyl-3-methylcyclohexane and explain clearly which one predominates. (b) What is polarimetry? The specific rotation of (R)-carvone is - 61°. A chemist prepared a 750 mg mixture of (R)-carvone and its enantiomer in 10 ml of ethanol and placed the solution in a 10 cm polarimeter cell. The observed rotation was - 4.125°. Calculate the specific rotation for the above mixture. What is meant by enantiomeric excess? Then determine the % enantiomeric excess (% ee) in the mixture. (i) (ii) (iii) What % of the mixture is (R)-carvone and (S)-carvone?

Draw the most stable conformation of the molecule shown below. The most stable conformation is the one in which

2

Which of the following is the correct Newman projection for the following compound as viewed down the indicat conformation shown? CO II O III O IV OV CH3 CH3 CH31 CH3 CI || Br Br H CH3 CH3 ||| Br CH3 CH3 IV CI Br CH3

Font Paragraph Using a Newman projection, draw the most stable conformation of CH2-CH2. | ОН ОН

In the most stable chair conformation of the cyclohexane below, how many methyl groups would be axial? CH3 CH3 three zero two all four CH3 CH3

Please show reaekson and don't use hend raiting

When you obtained a geometry optimized structure of methylcyclopentane, did you determine the energy of the most stable conformation? Why or why not?

Which of the following is an accurate conformational drawing for compound Z? Z