The E/Z-selectivity in the formation of silylketene acetals derived from phenylacetate esters, mediated by LiHMDS, has been studied by in situ NMR techniques. The formation is seen to be highly E-selective with use of the newly developed protocol. Isolated aryl-substituted silylketene acetals are now attainable with high levels of E-geometrical purity in excellent yield.
Harker, W. R. R., Carswell, E. L., & Carbery, D. R. (2010). A practical protocol for the highly E-selective formation of aryl-substituted silylketene acetals. Organic Letters, 12(16), 3712-3715. https://doi.org/10.1021/ol101580y