has been put to advantage in the asymmetric Mizoroki-Heck reaction.
17/02/2009 · Dounay, A
Wada 13 Desymmetrizing Heck Reactions Masakatsu Shibasaki and Takashi Ohshima 14 Combinatorial and Solid-Phase Syntheses Thierry Muller and Stefan Brase 15 Mizoroki-Heck Reactions: Modern Solvent Systems and Reaction Techniques Werner Bonrath, Ulla L-etinois, Thomas Netscher and Jan Schutz 16 The Asymmetric Intramolecular Mizoroki-Heck Reaction in Natural Product Total Synthesis Amy B.
Methods - Synthesis & Techniques
Owing to their unusual structural motifs and promising pharmacological properties, colchicine (1) and NCME (2) have attracted considerable attention from synthetic chemists, which has resulted in several elegant total syntheses of 1 and 2. Recently, we developed an enantioselective synthesis of colchicine (1) from commercially available and inexpensive 2,3,4-trimethoxybenzaldehyde (5). The challenging tricyclic 6–7–7 core of colchicinoids was efficiently introduced using an intramolecular oxidopyrylium-mediated [5 + 2] cycloaddition reaction. In our continuing efforts toward the synthesis of biologically active natural products, we herein describe a modified concise and highly enantioselective synthesis of colchicine using the Wacker oxidation for the regioselective construction of the highly oxidized tropolone C-ring. Moreover, asymmetric total syntheses of β-lumicolchicine and NCME were also achieved.