Lewis Acid Assisted Triple-Aldol Cascades

Significance

The authors report the triflimide-catalyzed aldolization of simple aldehydes with acetaldehyde-derived super silyl enolate. Under carefully optimized reaction conditions including organoiodide additives, such as phenyl iodide or iodophenylacetylene, the reaction was driven to follow a triple-cascade pathway. The obtained products, all-syn-configured protected 1,3,5-triols, were obtained in high yields. The very exclusive diastereoselectivity was governed by the use of the super silyl protecting group, thus delivering high steric bulk for 1,3-stereocontrol.