2004

AlkaloidsU 0600 Stereoselective Synthesis of Naturally Occurring Unsaturated Amide Alkaloids by

a Modified Ramberg—Baecklund Reaction. — The convenient approach to unsat-urated amide alkaloids of type (II) (14 examples) involves the title reaction as key step. By treatment of sulfones of type (I) with CBr2F2 in the presence of alumina-supported KOH in methylene chloride, a facile rearrangement occurs with formation of a new double bond having the (E)-configuration. — (LI, Y.; ZHANG, Y.; HUANG, Z.; CAO*, X.; GAO, K.; Can. J. Chem. 82 (2004) 5, 622-630; State Key Lab. Appl. Org. Chem., Inst. Org. Chem., Lanzhou Univ., Lanzhou 730000, Gansu, Peop. Rep. China; Eng.) — Klein

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