1.
J Org Chem
; 77(14): 5942-55, 2012 Jul 20.
Artículo
en Inglés
| MEDLINE
| ID: mdl-22703563
RESUMEN
The tandem chain extension-aldol (TCA) reaction of ß-keto esters provides an 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.