[Hazel]

Can somebody write all stereoisomers of 1,3-diphenylpropane(PhCHCH3CHCH3CHCH3Ph) in fischer projection??

Thanx a lot...!

[Dan]

Yes, but you try it first. (forum rules).

What are you having difficulty with specifically? Do you know what a Fischer projection is?

PhCHCH₃CHCH₃CHCH₃Ph is not 1,3-diphenylpropane, it would be something like 3-methyl-2,4-diphenyl-pentane.

[Hazel]

Oh yea..Thanks to point out my mistake,Dan.

Actually, I have done the question but I don't has any Chem drawing software to illustrate it.
The main problem I found was how many stereoisomers do this compound has?
Since it has two identical stereocenter,do it means it just has 2 stereoisomers(which is enantiomers) instead of 4?

Heaps of thanks.

[AWK]

Exactly the same number as tartaric acid (can be easily found over internet)

[sjb]

Exactly the same number as tartaric acid (can be easily found over internet)

Aside: Are there? Is there not a difference in the compound given where the two outside chiral centres (carbons 2 and 4) have opposing configurations, but carbon 3 is either R or S?

S

[Hazel]

The third Carbon should be no R,S configuration,right?As it is not a stereocarbon.

Thanks,I got the idea frm tartaric acid.

[AWK]

No change in number of isomers if the part between two chiral center is achiral

[sjb]

Ahh, point taken.

I think I see my confusion. Sorry to confuse you (was still looking at 3-methyl-2,4-diphenyl-pentane)

edit typo

[sjb]

To clarify what I was thinking.

If you draw out the 5-carbon chain of the meso form of 3-methyl-2,4-diphenyl-pentane) in a certain way, you have 2R,4S for the two carbons with phenyl substituents. But the methyl group in the middle can either be on the same face or the reverse face of the chain compared to the pheny groups. I think these are two different compounds, but how do you name them appropriately, as the two groups on either side are effectively the same?

S