ORGN 483 |
Progress toward the enantiospecific, stereospecific total synthesis of Nb-demethylalstophylline oxindole
| Xiangyu Z. Wearing and James M. Cook. Department of Chemistry, University of Wisconsin-Milwaukee, 3210 N. Cramer St., Milwaukee, WI 53211 |
An enantiospecific total synthesis of alstonisine 1 from the commercially available D-(+)-tryptophan via the asymmetric Pictet-Spengler reaction and enantiospecific OsO4 oxidation has been accomplished. It is felt that this approach will provide a method to make either oxindole, diastereomeric at C(7), in the 6-methoxyindole series. This strategy demonstrates the utility of the Pictet-Spengler reaction in the 6-methoxy series as well. Recently, the synthesis of ring-A substituted tryptophans via a palladium catalyzed heteroannulation process was executed which provided entry into 6-methoxytryptophan on multihundred-gram scale. With this material in hand, an asymmetric Pictet-Spengler reaction and a Dieckmann cyclization were then carried out to provide the 11-methoxytetracyclic ketone, a potential intermediate toward the total synthesis of Nb-demethylalstophylline oxindole 2. |
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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
Sci-Mix
8:00 PM-10:00 PM, Monday, March 29, 2004 Anaheim Convention Center -- Hall A, Sci-Mix
Division of Organic Chemistry
The 227th ACS National Meeting, Anaheim, CA, March 28-April 1, 2004
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