The following two molecular structures have two chiral centers, so in total four chiral centers:


I did the absolute configuration multiple times and I keep getting R,R and S,S, which should be enantiomers. My book says these two are “identical molecules that are superimposable”. What am I doing wrong?

  • 3
    $\begingroup$ These two are enantiomers. $\endgroup$ Oct 21, 2022 at 10:37
  • $\begingroup$ Just try superimposing these two structures! BTW your CIP assignments are incorrect. Assignments to bicyclic compounds are not straightforward. Reading left to right, they are (1S,4R)-bicyclo[2.2.1]heptan-2-one and (1R,4S)-bicyclo[2.2.1]heptan-2-one. (Take a look at the case of camphor here. (Don’t be confused by the R,R assignment to camphor.) $\endgroup$
    – user55119
    Oct 21, 2022 at 19:25


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