General Preparation of 1-Substituted (E)-1,3-Dienes under Mild Conditions

We describe the stereoselective synthesis of highly functionalized 1-substituted (E)-1,3-dienes by reductive β-elimination of 2-chloroallyl acetates, derived from the indium-promoted allylation of aldehydes with 1,3-dichloropropene and subsequent acetylation. The procedure is mild, straightforward, and simple, and it is generally applicable to a very diverse range of functionalized substrates.