[rleung]

Hey,

I am not really sure what the following molecule is.  At first, I thought it was a twisted boat conformation of the cyclohexane, but a closer look disconfirmed that possibility.  I then thought it was a twisted conformation of the cyclobutane.

The book asks me to say what relationship the following structure has with its mirror image.  The answer is that they are the same structure, but when I build the molecular models, I do not see that (I did not twist the structure since I don't want to break my sp3 pieces, so I built the untwisted versions).  I am not sure whether I am building the structure wrong or whether I am wrong about the structure being a cyclobutane.  I have included pictures of my molecular models below.

Thanks so much.

Ryan

[rleung]

This is the model of the left structure.

[rleung]

This is the model of its mirror image, which does not seem to be superimposable on its first structure.

[movies]

I think that those are actually two cyclopropane rings.

Good luck building a model of those though!

[arnyk]

Yup looks like two cyclopropanes with a couple methyl groups each side.

[Winga]

You can see that the wedge line is stopped at the centre carbon.

[Mitch]

movies: Whats that class of cyclopropanes called? I can't remember?

[AWK]

1,2,3,4-tetramethylspiro[2,2]pentane

http://www.chem.qmul.ac.uk/iupac/spiro/

[movies]

movies: Whats that class of cyclopropanes called? I can't remember?

There is a specific name for them?  I haven't encountered it.

They have the same kind of symmetry as chiral allenes, so maybe it has something to do with that?