194933-40-9Relevant academic research and scientific papers
Developing microcolin A analogs as biological probes
Mandal, Amit K.,Hines, John,Kuramochi, Kouji,Crews, Craig M.
, p. 4043 - 4047 (2007/10/03)
Three microcolin A and B analogs have been synthesized. Their biological activity profiles were evaluated against several cell lines, revealing the existence of a structural determinant whose role in mediating the antiproliferative effect of the microcoli
Synthesis of Microcolin B, a Potent New Immunosuppressant Using an Efficient Mixed Imide Formation Reaction
Andrus, Merritt B.,Li, Wenke,Keyes, Robert F.
, p. 5542 - 5549 (2007/10/03)
Microcolin B, a potent new immunosuppressant isolated from blue-green alga Lyngbya majuscula off the Venezuelan coast, has been made using a methyl-directed asymmetric hydrogenation reaction with rhodium on alumina catalyst on lactone 4 for the synthesis of the key (R,R)-2,4-dimethyl-octanoic acid fragment 1. A new, direct mixed imide formation reaction was also developed for the production of the unusual prolylpyrrolen-2-one 2 portion of microcolin. The pentafluorophenyl ester of CBZ-proline 5 was reacted with the lithium imidate of lactam 6, providing the mixed imide in 80% yield. Coupling of acid 1 with the N-terminus of the tripeptide, followed by coupling with pyrrolylproline 2, gave microcolin B. The new mixed-imide forming reaction was also applied to a formal total synthesis of microcolin A. The pentafluorophenyl ester of TBS-protected cis-hydroxyproline was coupled with lactam 6, and the resultant imide was converted to the key pyrrolylproline made previously for microcolin A.
