Preparation of Enolate–Homoenolate Species as (Z)‐γ‐Siloxyallylmetal Equivalents: Sequential 1,4‐Addition of Bis(iodozincio)methane to 1,4‐Dicarbonylbutenes and Cyclopropanation

Enolate–homoenolate equivalents 1 can be prepared in one step by the title reaction. They act as functionalized Z-γ-siloxyallyl zinc reagents 2 by undergoing ring opening in the presence of a Lewis acid. Addition of 2 to tosylimines gives vic-amino alcohols with high diastereoselectivity, presumably due to a fixed conformation resulting from coordination of the metal atom.