Sciencemadness Discussion Board

Odd lettering in IUPAC name

thesmug - 13-3-2014 at 21:58

I am sorry if this is too much of a beginner question but, earlier today I was looking at gibberellic acid on wikipedia and noticed how the IUPAC name had a bunch of weird letters at the beginning. In fact, here it is:
(3S,3aS,4S,4aS,7S,9aR,9bR,12S)-7,12-dihydroxy-3-methyl-6-methylene-2-oxoperhydro-4a,7-methano-9b,3-propenoazuleno[1,2-b]furan-4-carboxylic acid
What I am confused by is the 3S,3aS,4S etc. stuff. What does it mean? I've seen it before on other molecules which were also from biological origins, if that makes any difference.

organichem - 13-3-2014 at 22:20

That's a kind of nomenclature for stereoisomers where the configuration is decribed with the
aid of different priorities: CIP - Wiki

thesmug - 14-3-2014 at 05:22

Thank you!