What are the steps to convert Newman projections to bond line notations?

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Answer 1 · 2015-08-13T18:41:09

You look for the longest chain, then you add the substituents.

Here is the Newman projection of a hydrocarbon. What is its bond-line notation?

people.bethelks.edu
(from people.bethelks.edu)

Step 1. Find the longest continuous chain of carbon atoms.

There is one $C$ $"C"$ atom at the centre of the circle and a second one hidden at the back of the circle.

A methyl group off the back adds a third $C$ $"C"$ atom.

On the front carbon, the ethyl group has the longest chain, for another two $C$ $"C"$ atoms.

We draw a 5-carbon chain.

opsin.ch.cam.ac.uk
(from opsin.ch.cam.ac.uk)

Step 2. Locate the substituents.

Let's call the terminal $C$ $"C"$ of the ethyl group $C-1$ $"C-1"$ .

Then the front carbon in the circle is $C-3$ $"C-3"$ and the hidden carbon is $C-4$ $"C-4"$ .

$C-3$ $"C-3"$ has a methyl group attached, while $C-4$ $"C-4"$ has only $H$ $"H"$ atoms.

So we have a 5-carbon chain with a methyl group at $C-3$ $"C-3"$ .

opsin.ch.cam.ac.uk
(from opsin.ch.cam.ac.uk)

And we have our bond-line structure.