Cover Picture: Fast and Efficient Synthesis of Z ‐Enol‐γ‐Lactones through a Cycloisomerization Reaction of β‐Hydroxy‐γ‐Alkynoic Acids Catalyzed by Copper(I) under Microwave Heating in Water (Asian J. Org. Chem. 6/2015)

The cycloisomerization reaction of γ‐alkynoic acids mediated by transition‐metal catalysts has become a successful strategy for accessing enol lactones during the past few years. In their Full Paper on page 545, Cecilio Alvarez‐Toledano and co‐workers developed a fast and efficient protocol for the regio and diastereoselective cycloisomerization of β‐hydroxy‐γ‐alkynoic acids, catalyzed by the inexpensive and air‐stable catalyst CuBr (5 mol%) in water under microwave heating. This method provides rapid access to a variety of highly functionalized Z ‐enol‐γ‐lactones in good yields under mild reaction conditions.