DMAP‐Catalyzed [4 + 2] Cycloaddition of α,β‐Unsaturated Carboxylic Acids with Ketones for Synthesis of α,β‐Unsaturated δ‐Lactones

Abstract

The DMAP‐catalyzed [4 + 2] cycloaddition of α,β‐unsaturated carboxylic acids with ketones furnishing α,β‐unsaturated δ‐lactones in good yields (up to 80%) is described, which is the first example of remote γ‐C(sp3)‐H activation of α,β‐unsaturated carboxylic acids facilitated by DMAP, a pyridine‐based catalyst. Copyright © 2017 John Wiley & Sons, Ltd.