Draw Newman projections along the C3-C4 bond to show the most stable and least stable conformations of 3-ethyl-2,4,4-trimethylheptane
Solution 47SP :
A Newman projection is a way to look at the conformation of a noncyclical molecule. It visualizes chemical conformations of a carbon-carbon chemical bond from front to back of the compound. The front carbon atom is represented by a dot and the carbon atom at the back is represented as a circle. The front carbon atom is called as proximal and the back carbon atom is called distal.
Sometimes there can be various newman projections for a molecule or compound as carbon atoms in the compound are linked by single bonds and the bonds are able to freely rotate, allowing for various conformations.
There are mainly 2 conformations for newman projection - eclipsed conformation and staggered conformation.
Among these 2 conformations, staggered conformation is most stable than the eclipsed conformation.
The compound, 3-ethyl-2,4,4-trimethylheptane has molecular formula of C12H26. The structure of the compound would look as shown below :
The staggered conformation of the Newman projections along the C3-C4 bonds is shown below :
The above conformation is the most stable conformation as the 2 larger groups -the methyl(CH3) and the ethyl(CH3CH2) group are anti placed because of which there is very less torsional strain and gauge strain.