ORGN 469 |
| Robin B. Kinnel and Jakub Sroubek. Department of Chemistry, Hamilton College, 198 College Hill Road, Clinton, NY 13323 |
| Bromoallene acetogenins are secondary metabolites of importance as immune response-mediating agents from the algae Laurencia. Presumably a bromoperoxidase (BPO) enzyme directs an internal cyclization reaction on alcohol precursors that gives rise to these bromoallene species. To investigate the muddy stereochemistry of this reaction we prepared a precursor by alkylating cyclopentanone-SAMP hydrazone enantioselectively with trans-pent-2-ene-4-yn-ol mesylate, hydrolyzing the hydrazone with oxalic acid and then reducing the resulting ketone to a cis-alcohol with the potassium complex K-Selectride. Non-selective cyclization with NBS afforded the diastereomeric bromoallenes in good yield. We shall describe our results and report on our current efforts at cyclization using a variety of enzyme preparations. |
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Total Synthesis, Asymmetric Reactions and Syntheses, Bioorganic
9:00 AM-11:00 AM, Wednesday, March 31, 2004 Anaheim Convention Center -- Hall C, Poster
Division of Organic Chemistry |