Browsing by Author "Tian, Xinrong"

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    Chemistry of oxa- and aza-bicyclic(4.1.0)heptenes, total synthesis of (+)-pancratistatin
    Tian, Xinrong (Virginia Tech, 1995)
    Vinyloxiranes 6a-b and vinylaziridines 7a-b were prepared efficiently from halocyclohexadiene-cis-diols 1. Reactions of 6 and 7 with a variety of organometallic reagents were investigated in order to determine the stereo- and regiochemistry of ring opening with carbon nucleophiles. The results indicate that 6 and 7 could serve as useful new synthons for C-disaccharides and Amaryllidaceae alkaloid syntheses. The utility of synthon 7b has been demonstrated by a concise enantiocontrolled synthesis of (+)-pancratistatin (9). The key step involved the SN2 opening of 7b with the aryl cyanocuprate derived from amide 217 to generate the pivotal cyclization precursor.
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    Synthesis of (+)-pancratistatin
    (United States Patent and Trademark Office, 1997-05-06)
    This is described an improved process for the asymetric synthesis of (+)-Pancratistatin utilizing aziridines as the starting materials.