I think it is great that some discussions are getting started. I second
Cornelius' enthusiasm for Yevdokimov Artiom's definition of chirality.
He points out rightly, that chiral compounds are molecules that are not
identical with their mirror image. This definition provides the easiest test
for chirality and it is valid for all the different kinds of chirality. E,Z
stereoisomers are diastereomers, they are not necessarily chiral compunds.
The second point raised by Cornelius might deserve some additional comments:
the molecule, which he used to illustrate it:
> OH
> !
> H-C-CH3
> !
> H-C-CH3
> !
> OH
is 2,3-butan-diol. It does form stereoisomers, however. Of the four possible
stereoisomers (2R,3R; 2R,3S; 2S,3R; 2S,3S) two are identical (and not
chiral) namely the (R,S) form and the (S,R) form. They are called the
meso-form of this diol. (2R,3R)- and (2S,3S)-butandiol are enantiomers (i.e.
mirror images) of each other (this means, they are chiral).
I am looking forward to having a great glossary for our course. It will be
due to the people who have just started writing definitions, like Yevdokimov
Artiom.
Have a nice time,
Achim
Achim Treumann tel. +44-382-344301
Department of Biochemistry fax +44-382-322583
University of Dundee
Dundee DD1 4HN, Scotland, UK email a.treumann@dundee.ac.uk