Concise Synthesis of Coscinamide B, a Bisindolic Enamide from Marine Sponge

Abstract

An efficient, four-step synthesis of coscinamide B (2) from tryptamine is reported, in which a one-pot benzylic bromination and subsequent in situ dehydrobromination in the absence of an added base is the key step.

Key words

coscinamide B - bisindolic enamide - synthesis - tryptamine - in situ dehydrobromination

References

• 1a Kagamizono T. Sakai K. Arai K. Kobinata K. Osada H. Tetrahedron Lett.  1997,  38:  1223 
• 1b Azumi K. Yokosawa H. Ishii S. Biochemistry  1990,  29:  159 
• 1c Andersen RJ. Tetrahedron Lett.  1978,  29:  2541 
• 1d Dumdei E. Andersen RJ. J. Nat. Prod.  1993,  56:  792 
• 1e Toske SG. Jensen PR. Kauffman CA. Fenical W. Tetrahedron  1998,  54:  13439 
• 1f Kirkup MP. Moore RE. Tetrahedron Lett.  1983,  24:  2087 
• 2 Suescun L. Mariezcurrena RA. Mombru AW. Davyt D. Monta E. Acta Crystallogr., Sect. A  1999,  55:  211 
• 3 Bokesch HR. Pannell LK. McKee TC. Boyd MR. Tetrahedron Lett.  2000,  41:  6305 
• 4 Kuramochi K. Osada Y. Kitahara T. Chem. Lett.  2002,  128 
• 5 Shaw KNF. McMillan A. Gudmundson AG. Armstrong MD. J. Org. Chem.  1958,  23:  1171 
• 6 Desarbre E. Coudret S. Meheust C. Merour JY. Tetrahedron  1997,  53:  3637 
• 7a March J. Advanced Organic Chemistry   4th ed.:  Wiley; New York: 1992.  p.1009 ; and the references cited in reference 133 on this page
• 7b Kamimura A. Ono N. Chem. Commun.  1988,  1278