[SIUEWIHG8435JDFGJ]

Sorry for all the questions, organic chemistry isn't exactly my strong point. This practice problem is asking about pairs of compounds, whether or not they're diastereomers, enantiomers, or the same compound.



For I, I said they were the same compound because they have the same connectivity and are superimposable once you rotate them.

For II, I said they were the same compound too after I translated the Newman projection to a Fischer project. They appear to be the same.

For III, I said they were diastereomers because they have the same connectivity, are not superimposable, and are not mirror images of each other.

For IV, I said they were diastereomers because they have the same connectivity, are not superimposable, and are not mirror images of each other.

I'm using a flowchart similar to http://i.imgur.com/QURKVt6.gif to help me determine what they of isomer they are. The one I'm least sure of is III, but after drawing it over and over again, I /think/ they're the same.

[Dan]

Have another go at II and III. Build models.