The D-site loses this structure due to distortion by Glu and Asp side chains in the mechanism of lysozyme. The Zimmerman-Traxler model predicts the aldol reaction's stereochemistry (-5[1])by assuming the transition state has this specific structure and analyzing the steric interactions. Transition states with this structure are thermodynamically favored for [3+3]-rearrangements like the Claisen and (*) Cope rearrangements. The Newman projection for this conformation is fully staggered, while it is fully gauche for a different conformation that experiences (-5[1])■END■