An Efficient Route to 4/5/6 Polycyclic ?-Lactams

September 30, 2017 | Autor: F. Robert-Peillard | Categoría: Organic Chemistry, Ionic Liquids, Metathesis
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2005 Fused pyrrole derivatives R 0160 An Efficient Route to 4/5/6 Polycyclic β-Lactams. — The route to title compounds the synthesis of bicyclic diene (III) and following cycloaddition reaction with 14- 128 involves different dienophiles. In contrast to the methods reported previously for the synthesis of 4/6/6 and 4/7/6 polycyclic lactams, the present strained bicyclic diene (III) affords alternative reaction conditions both for its synthesis and for its reaction with dipolarophiles. By changing from Grubbs' first-generation catalyst to the more active Grubbs' second-generation catalyst, the yield of (III) can be increased from 29 to 86%. To obtain good yields in the cycloaddition reactions with compounds (VI), (IX), and (XII), the reactions are performed in LiClO4/Et 2O or ionic liquid media. — (DESROY, N.; ROBERT-PEILLARD, F.; TOUEG, J.; DUBOC, R.; HENAUT, C.; RAGER, M.-N.; SAVIGNAC*, M.; GENET, J.-P.; Eur. J. Org. Chem. 2004, 23, 4840-4849; Lab. Synth. Sel. Org. Prod. Nat., CNRS, Ec. Natl. Super. Chim., F-75231 Paris, Fr.; Eng.) — Klein

2005

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