Renaissance of α-Methylene-γ-butyrolactones: New Synthetic Approaches

The amount of research activity concerning α-methylene-γ-butyrolactones and α-alkylidene-γ-butyrolactones has increased dramatically in recent years. This Review summarizes the structural types, biological activities, and biosynthesis of these compounds, concentrating on publications from the past 10 years. Traditional approaches to α-methylene-γ-butyrolactones and α-alkylidene-γ-butyrolactones are then reviewed together with novel approaches, including those from our own research group, reported more recently.