Preparation of 3-Allenyl-4-methylenetetrahydrofurans

Abstract A novel method for the preparation of 3-allenyl-4-methylenetetrahydrofurans via a Pd-catalyzed enyne cyclization reaction of propargyl 2-en-4-ynyl ethers under Suzuki coupling conditions is disclosed. The reaction proceeds via Pd activation of the terminal alkyne, cyclization, formation of the allenyl moiety, and reductive elimination, leading to the final product. This methodology offers several advantages, such as easy manipulation, mild reaction conditions, and easily accessible starting materials, providing a range of trisubstituted and 1,1-disubstituted allenyl(methylene)furan derivatives.