Stereoselective Three-Component Synthesis of <i>trans</i>-<i>e</i><i>ndo</i>-Decahydroquinolin-4-one Derivatives from Aldehydes, Aniline, and Acetylcyclohexene

The diastereoselective synthesis of trans-endo-decahydroquinolin-4-one (4) via a three-component reaction of aldehydes (1), anilines (2), and 1-acetylcyclohexene (3) in the presence of iodine in a one-pot reaction at room temperature is described. The short reaction time, easy workup, excellent yield, and mild reaction conditions make this novel annulation strategy both practical and attractive.