Dyotropic reaction
In organic synthesis, an important dyotropic reaction is the conversion of 4-substituted-gamma-lactones to butyrolactones. Type I dyotropic rearrangements also occur around carbon-oxygen bonds. One example is using heat to change RRSi1R3C-O-Si2R3 to RRSi2R3C-O-Si1R3.  (This reaction can go in both directions depending on temperature.) Another example is the 1,2-Wittig rearrangement. Dyotropic reactions can also happen with N-O bonds or N-N bonds.