Article
A Combined DFT Study and NMR Investigations of the Zinc Organometallic Intermediate Proposed in the Syn-Selective Tandem Chain Extension-Aldol Reaction of β-Keto Esters
Journal of Organic Chemistry
(2012)
Abstract
The tandem chain extension-aldol (TCA) reaction of β-keto esters provides a α-substituted γ-keto ester with an average syn:anti selectivity of 10:1. It is proposed that the reaction proceeds via a carbon-zinc bound organometallic intermediate potentially bearing mechanistic similarity to the Reformatsky reaction. Evidence, derived from control Reformatsky reactions and a study of the structure of the TCA intermediate utilizing DFT methods and NMR-spectroscopy, suggests the γ-keto group of the TCA intermediate plays a significant role in diastereoselectivity observed in this reaction. Such coordination effects have design implications for future zinc mediated reactions.
Disciplines
Publication Date
2012
Publisher Statement
This is an Accepted Author Manuscript obtained from PMC. The publisher's final edited version of this article is available at Journal of Organic Chemistry.
Citation Information
Karelle Aiken, Eger A. Wilhelm, Craig M. Williams, Carley M. Spencer, et al.. "A Combined DFT Study and NMR Investigations of the Zinc Organometallic Intermediate Proposed in the Syn-Selective Tandem Chain Extension-Aldol Reaction of β-Keto Esters" Journal of Organic Chemistry Vol. 17 Iss. 14 (2012) Available at: http://works.bepress.com/karelle_aiken/13/