the-aldol-reaction-is-stereospecific-and-proceeds-via-the-zimmermantraxler-trans

Question

The aldol reaction is stereospecific and proceeds via the Zimmerman–Traxler transition state depicted below.

(a) Illustrate the arrow-pushing mechanism for step A and step B.

(b) Explain why this mechanism is favorable.

Accepted Answer

This mechanism is favored because the chair-like transition state lowers the activation energy and metal chelation provides additional stabilization.

Answer

This mechanism is favored because the chair-like transition state increases system entropy and metal chelation only stabilizes the reactants.

Answer

This mechanism is favored because the boat-like transition state lowers the activation energy but metal chelation has no effect on stability.

Answer

This mechanism is favored because the chair-like transition state raises the activation energy and metal chelation destabilizes the intermediate.