both geometrical & optical isomers are accepted.Please give the number & structure with the IUPAC name if possible!!! please help me!!!! this is an important assingment for me!!!
2007-04-20 18:06:47 · 3 answers · asked by soma 2 in Science & Mathematics ➔ Chemistry
Been a while since I've done stereochemistry, but I'll reason my way through this.
Ok, 2,3 dibromobutane.....there are no double bonds so that means everything has free rotation, so no geometrical isomers. However, you do have two stereo centers here (the 2,3 positions). So, you could have R,R R,S S,R S,S
However, since the molecule is symmetrical (you can count carbons from either side and have the same structure) the R,S and S,R are the same molecule...so you have 3 stereo isomers and no geometric.
With 2,3 diiodopentane you again have no double bonds, so no cis or trans type geometric isomers. However, this molecule is not symmetrical (you can only count from one direction to get the structure) so in this case the R,S and S,R isomers are unique and you have 4 stereo isomers.
As for IUPAC naming...the R and S go with the 2,3 I think...someone correct me if I'm wrong...but I believe it would be like 2R,3R-dibromobutane, or 2S,3R-dibromobutane, etc.
2007-04-20 18:46:45 · answer #1 · answered by Anonymous · 1⤊ 1⤋
2 3-dibromobutane
2016-10-06 23:33:38 · answer #2 · answered by ? 4 · 0⤊ 0⤋
4 each.
2007-04-20 18:36:24 · answer #3 · answered by ag_iitkgp 7 · 0⤊ 0⤋