Total syntheses of (+/-)-fawcettimine, (+/-)-fawcettidine, (+/-)-lycoflexine, and (+/-)-lycoposerramine B | Posted on:2013-11-14 | Degree:Ph.D | Type:Dissertation | University:Colorado State University | Candidate:Pan, Guojun | Full Text:PDF | GTID:1451390008463758 | Subject:Chemistry | Abstract/Summary: | | The total syntheses of (+/-)-fawcettimine, (+/-)-lycoflexine, (+/-)-fawcettidine, and (+/-)-lycoposerramine B have been accomplished through an efficient, unified, and stereocontrolled strategy that required sixteen, sixteen, seventeen, and seventeen steps, respectively, from commercially available materials. The key transformations involve: (1) a Diels-Alder reaction between a 1-siloxy diene and an enone to construct the cis-fused 6,5-carbocycles with one all-carbon quaternary center, and (2) a Fukuyama-Mitsunobu reaction to form the azonine ring. Access to the enantioselective syntheses of these alkaloids can be achieved by kinetic resolution of the earliest intermediate via a Sharpless asymmetric dihydroxylation. | Keywords/Search Tags: | Syntheses | | Related items |
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