@article{74dce2b7504c4e5c927fda2a8c7cac2b,
title = "Synthesis of 3-alkenyl-Δ2-cephems by copper(I) chloride-promoted alkenylation of 3-trifluoromethylsulfonyloxy-Δ3-cephem with alkenyltributyltins",
abstract = "Synthesis of 3-alkenyl-Δ2-cephems 3 was performed in regioselective by copper(I) chloride-promoted alkenylation of 3-trifluoromethylsulfonyloxy-Δ3-cephem 1 with alkenyltributyltins. Subsequent Diels-Alder reaction of the 3-vinyl-Δ2-cephem 3a with acrolein opened a new access to C(2)-C(3) fused tricyclic cephalosporin 9.",
author = "Hideo Tanaka and Sumida, {Shin Ichi} and Sigeru Torii",
note = "Funding Information: The Diels-Alder reaction of 3-vinyl-A2-cephem 3a with acrolein (4 ~equiv.) in dichloromethane at ambient temperature for 21 h afforded the tricyclic cephalosporin 9 (Y = CHO, 77%) together with a dimer 10 (7%). The formation of the dimer 10 was performed more effectively (92%) by heating 3a alone in dichloromethane at 40 °C for 5 days. These facts suggest that 3a can work not only as a diene but also as a dienophile in the Diels-Alder reaction. Further application of the alkenyl-A2-cephems 3 to the synthetic useful [~-lactam antibiotics is in progress. We acknowledge financial support by a Grant-in-Aid for Scientific Research (06453140, 05403025) from The Ministry of Education, Science, and Culture of Japan. Thanks are due to the SC-NMR Laboratory of Okayama University for obtaining NMR spectra.",
year = "1996",
month = aug,
day = "12",
doi = "10.1016/0040-4039(96)01289-0",
language = "English",
volume = "37",
pages = "5967--5970",
journal = "Tetrahedron Letters",
issn = "0040-4039",
publisher = "Elsevier Limited",
number = "33",
}