Palladium-Catalyzed Coupling Reaction of an Enol Nonaflate with (Vinyl)tributylstannanes and Acetylenes: A Highly Stereoselective Synthesis of 8,18-13C2-Labeled Retinal - Wada, Akimori; Ieki, Yasuhiro; Nakamura, Saeko; Ito, Masayoshi (Synthesis, 2005)