A facile preparation of exo-cyclic conjugated dienes fused to lactams or lactones via intramolecular coupling of acetylenes and their behavior in Diels-Alder reactions.
[reaction: see text] Treatment of bis-acetylenic amides or esters 3 with (eta(2)-propene)Ti(O-i-Pr)(2) generates functionalized titanacyclopentadienes which, upon hydrolytic workup, give exo, exo-cyclic conjugated dienes 4 in good yields. Some regio- and stereochemical aspects of their Diels-Alder reaction with dienophiles are also disclosed.
Urabe
H
H
Department of Biomolecular Engineering, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8501, Japan.
Nakajima
R
R
Sato
F
F
D000114:Acetylene / Q000031:analogs & derivatives / Q000737:chemistry*; D000475:Alkenes / Q000138:chemical synthesis*; D007202:Indicators and Reagents; D007769:Lactams; D007783:Lactones; D008968:Molecular Conformation; D015394:Molecular Structure; D013329:Structure-Activity Relationship
D000475:Alkenes; D007202:Indicators and Reagents; D007769:Lactams; D007783:Lactones; D000114:Acetylene