How do you name alkanes from Newman projections?
To name an alkane from a Newman projection, you convert the projection to a line structure; then you write the IUPAC name.
Name the alkane shown in the following Newman projection.
One C atom is at the front of the circle. Another C atom hides behind the circle. You must trace the bonds through the structure.
Pick the longest chain from one of the three groups attached to the front C atom.
Since they are all CH₃ groups, pick one of them. Label that CH₃ carbon C-1.
C-1 attaches to C-2, the front carbon.
C-2 attaches to the other two CH₃ groups and to the hidden C-3. Label the front carbon C-2.
C-3 attaches to two H atoms and a CH₂CH₃ group. Pick the longest group (CH₂CH₃) to form the rest of the chain.
Label the CH₂ carbon as C-4.
Label the CH₃ carbon as C-5.
You now have the longest chain in the molecule.
Draw the line structure.
C-1 = CH₃
C-2 = C(CH₃)₂
C-3 = CH₂
C-4 = CH₂
C-5 = CH₃
Your structure should look something like the structure below.
Write the IUPAC name.
The alkane is 2,2-dimethylpentane.