Main article : Claisen rearrangement Discovered in 1912 by Rainer Ludwig Claisen , the Claisen rearrangement is the first recorded example of a ( 3,3 ) - sigmatropic rearrangement .
Discovered in 1912 by Rainer Ludwig Claisen , the Claisen rearrangement is the first recorded example of a ( 3,3 ) - sigmatropic rearrangement .