Predict the product of the following sigmatropic rearrangements. Be sure to rationalize the stereochemical outcome with a chair-like transition state.
(d)

Sigmatropic rearrangements are a type of pericyclic reaction where a sigma bond adjacent to one or more pi systems migrates across the molecule. These reactions are classified by the number of atoms involved in the migration, denoted as [i,j]-shifts. Understanding the nature of these shifts is crucial for predicting the structural changes in the product.

A chair-like transition state is a conformation that resembles the chair form of cyclohexane, often adopted during pericyclic reactions to minimize steric strain and maximize orbital overlap. This conformation is particularly relevant in sigmatropic rearrangements, as it helps rationalize the stereochemical outcome by providing a stable, low-energy pathway for the reaction.

Stereochemistry in pericyclic reactions is governed by the conservation of orbital symmetry, as described by the Woodward-Hoffmann rules. These rules predict the stereochemical outcome based on the symmetry of the molecular orbitals involved. In sigmatropic rearrangements, understanding how the transition state influences stereochemistry is essential for predicting the configuration of the product.