 These substrates may undergo the oxy-Cope rearrangement upon deprotonation, affording δ,ε-unsaturated carbonyls.This tandem sigmatropic strategy has been employed in the synthesis of some natural products, including brevicomine and oxocrinol.One variation of the 2,3-Wittig rearrangement is the Wittig-Still rearrangement 

Rearrangements must be carried out at temperatures below −60 °C to avoid competitive [1,2]-rearrangement.