ORGN 46 |
| Ji Duck Kim, In Soo Kim, Cheng Hua Jin, and Young Hoon Jung. College of Pharmacy, Sungkyunkwan University, Suwon 440-746, South Korea |
| We have developed the novel one-pot synthetic method for regioselective and stereoselective N-protected amines through the reaction of various ethers with chlorosulfonyl isocyanate (CSI). Also, we found a novel technique to compare directly the stability of carbocations in the solution phase and established the stability order of the various carbocations. And we reported the cleavage of benzyl and p-methoxybenzyl protecting groups of alcohols and phenols in the presence of other functional groups using CSI. Also, we established that our CSI reaction is a competitive reaction of SNi and SN1 reaction according to the stability of carbocation intermediate. In this presentation, we report a stereoselective total synthesis of the (-)-cytoxazone, a novel 4,5-disubstituted-2-oxazolidinone compound isolated from Streptomyces species, which has shown cytokine modulating activity, based on the regioselective and stereoselective CSI reaction we developed. The total synthesis of (-)-cytoxazone was achieved in 6 linear steps from p-anisaldehyde. Key steps in this route are the regioselective and stereoselective introduction of N-protected amine group using our CSI reaction of anti-1,2-dimethyl ether and the subsequent regioselective cyclization of N-protected amino diol to give the 2-oxazolidinone unit of (-)-cytoxazone. We also found the optimum reaction conditions for the diastereoselective CSI reaction of anti- and syn-1,2-dimethyl ethers. The retention of configuration can be explained by the neighboring group effect.
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New Reactions and Methodology, Metal-Mediated Reactions, Heterocycles and Aromatics
8:00 PM-10:00 PM, Sunday, March 28, 2004 Anaheim Convention Center -- Hall A, Poster
Division of Organic Chemistry |
