Efficient synthesis of 4-(2′-alkenyl)-2,5-dihydrofurans via PdCl2-catalyzed coupling–cyclization reaction of 2,3-allenols with allylic halides

4-(2′-Alkenyl)-2,5-dihydrofurans can be efficiently synthesized via the PdCl2-catalyzed coupling–cyclization of allylic halides with 2,3-allenols in DMA at rt in moderate to good yields. The regioselectivity is different from that of the Pd(0)-catalyzed coupling–cyclization of organic halides with 2,3-allenols.