ORGN 533 |
| Dynamic diastereoselectivity during iron tricarbonyl promoted [6 + 2] ene spirocyclization of 1a and 1b, having a chiral center on the pendant side chain, was investigated and gave rise to products 2a and 2b instead of four possible isomers. From this reaction two chiral centers are generated, with absolute stereochemistry determined by the double bond geometry and the chiral center already present. 2a/b and the diene product from demetallation of 2a are proposed as potential intermediates for total synthesis of 18-deoxycytochalasin H. Furthermore, a stepwise second cyclization and a tandem double cyclization mediated by the iron tricarbonyl moiety was investigated. In order to apply both 2a/b to total synthesis, a iron tricarbonyl promoted carbonyl-ene reaction was also investigated.
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Physical Organic Chemistry, Metal-Mediated Reactions, Asymmetric Reactions and Syntheses
8:00 PM-10:00 PM, Tuesday, August 21, 2007 BCEC -- Exhibit Hall - B2, Poster
Division of Organic Chemistry |
