Converting a Newman projection into a bond-line structure

Challenge 1: Converting a staggered Newman projection to a wedge-and-dash structure

Question:

Translate the following Newman projection into a bond-line structure

Step 1: Convert the Newman projection into a Sawhorse projection

Before we dive into the wedge-and-dash structure, we first need to convert the Newman projection into a Sawhorse projection.

What’s the difference?

In a Newman projection, you’re looking straight down the bond connecting two carbons: one in front and the other at the back. A Sawhorse projection, on the other hand, shows the molecule from a tilted angle, revealing the bond between the front and back carbons more clearly.

Here’s how to do it:

• Draw a diagonal line to represent the bond between the front carbon (C1) and the back carbon (C2).
• Add the substituents on each carbon exactly as they appear in the Newman projection.

This gives you a clear view of the molecule’s 3D structure, which will make the next steps easier!

Step 2: Decide the viewing angle

Now that we have the Sawhorse projection, we need to figure out how we’re viewing it. Are we looking at it from the left side or the right side?

Why does the viewing angle matter?

The angle determines how we position the substituents in the final bond-line structure. For this challenge, we’ll look at the molecule from the right side.

Step 3: Translate into a bond-line structure

Using the Sawhorse projection and the chosen viewing angle, we’ll convert the substituents into the bond-line (wedge-and-dash) format.

Here’s how to translate substituents:

• Groups pointing straight up or straight down in the Newman projection stay in the plane of the page. Draw these as straight lines.
• Groups pointing towards you are drawn as wedges (solid triangles).
• Groups pointing away from you are drawn as dashes (dashed triangles).

For the front carbon (C1):

• CH₃ (up) → straight line pointing up.
• F (down, away from you) → dash pointing down.
• Br (down, towards you) → wedge pointing down.

For the back carbon (C2):

• CH₂CH₃ (down) → straight line pointing down.
• CH₃ (up, away from you) → dash pointing up.
• OH (up, towards you) → wedge pointing up.

Now you have all the substituents positioned correctly on the carbon-carbon bond in the bond-line structure!

Step 4: Review your structure

Take a moment to compare your bond-line structure with the original Newman projection.

• Do the substituents match the Newman projection?
• Are the wedges, dashes, and straight lines correctly placed?

If everything checks out, congratulations! You’ve successfully converted a staggered Newman projection into a bond-line structure. 🎉