Conjugated diynes underwent selective mono-titanation with a Ti(II) reagent to give 1:1 diyne-titanium alkoxide complexes, which reacted with proton, aldehyde, and another acetylene to give stereo-defined enynes, enynols, and dienynes.
Department of Biomolecular Engineering, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8501, Japan.
