Fig. 1: Strategies to access molecular skeleton rearrangement.
From: Mn(I)-catalyzed sigmatropic rearrangement of β, γ-unsaturated alcohols

a The traditional migratory patterns in Smiles, semi-pinacol, Beckmann, and Wolff rearrangements. b The sigmatropic shift in the Cope and Claisen rearrangement and the Witting rearrangement. c This work: Mn(I)-catalyzed 1,2-STR or 1,3-STR of α-aryl-β, γ-unsaturated alcohols.