Newman'Projection'Practice'
1'
Organic Chemistry I – Jasperse Newman Projection Practice
A. For each of the following, draw the best and worst Newman projection, relative to the bond
indicated.
1. Butane, relative to the C2-C3 bond
2. 1-chloropropane, relative to the C1-C2 bond
3. 2-methylbutane, relative to the C2-C3 bond
4. 2,2-dimethylbutane, relative to the C2-C3 bond
5. 2-chloro-2-methylpentane, relative to the C2-C3 bond
Note: Cl is smaller than methyl
B. Rotation Barriers.
6. Rank the rotation barriers relative to the indicated bonds, with 1 have the largest barrier
• For convenience, Et = ethyl and iPr = isopropyl
• Assume that a halogen, OH, or NH2 is smaller than a CH3 or any other alkyl group.
Et Et
Cl iPr Et
Et iPr
Et
Et
(See page 4 for some summary of operations/steps for handling Newman projections)
