Howard E. Zimmerman and his undergraduate student Marjorie Traxler proposed a stereochemical model to explain the outcome of Ivanov reaction and mechanistically similar Reformatsky Reaction.
Notice that the streochemistry of the products shown are relative and not absolute. Zimmerman-Traxler's seminal publication on this model, however, fails to show the most stable transition state to rationalize the reaction outcome. The transition state used in the paper had a clear unfavorable 1,3-pseudo-diaxial interaction (shown in red circles).
- Zimmerman, H. E.; Traxler, M. D. J. Am. Chem. Soc. 1957, 79, 1920.