Question

Question #fdfd3

Answer 1

Here's how I do it.

Step 1. Draw the parent alkane: octane.

Step 2. Add an ethyl group at `"C3"` and an isopropyl group at each of `"C4"` and `"C5"`.

Step 3. Add stereo wedges and dashes to the groups on `"C3, C4"`, and `"C5"` (the order doesn't matter — there are four stereoisomers).

Step 4. Add stereo dashes and wedges for the missing H atoms at `"C3, C4"`, and `"C5"`.

And you have a 3D wedge-dash structural formula of the molecule.

Here's a different type of 3D view for one of the other stereoisomers.