2
$\begingroup$

enter image description here

As shown above,we know there are two configurations possible for conjugated dienes.

Are they given any special names like we have cis and trans? This came up because while studying the Diels Alder reaction, it occured to me that maybe only the 'cis' like dienes will go through the reaction.

$\endgroup$
  • $\begingroup$ Go through $E -Z $ nomenclature. Here it is not possible ,but in any double bonds where the attached groups on one side is different, that is very useful. $\endgroup$ – Soumik Das Mar 14 '18 at 18:36
  • 2
    $\begingroup$ Yes, the terms "s-cis" (single bond cis) and "s-trans" (single bond trans) are often used to describe the geometrical relationship of the double bonds attached to the central single bond. See [this earlier answer]( chemistry.stackexchange.com/questions/44053/…) for more information as well as how those conformations affect the Diels-Alder reaction. $\endgroup$ – ron Mar 14 '18 at 18:54
3
$\begingroup$

The current version of Nomenclature of Organic Chemistry – IUPAC Recommendations and Preferred Names 2013 (Blue Book) supports various stereodescriptors that are used to denote specific conformers, in particular concerning conjugated dienes:

P-94.3.1.3 Stereodescriptors s-cis and s-trans

The spatial arrangement of two conjugated double bonds about the intervening single bond is described as ‘s-cis’ if ‘synperiplanar’ and ‘s-trans’ if ‘antiperiplanar’. This descriptor should not be applied to other systems such as N-alkyl amides (use ‘E/Z’ or ‘sp/ap’).

buta-1,3-diene

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.