Nitroso-Dienophile Additions to Dendralenes: A Short Synthesis of Branched Aminosugars

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• 作者：Ruomeng Wang ; Gomotsang Bojase ; Anthony C. Willis ; Michael N. Paddon-Row ; Michael S. Sherburn
• 刊名：Organic Letters
• 出版年：2012
• 出版时间：November 16, 2012
• 年：2012
• 卷：14
• 期：22
• 页码：5652-5655
• 全文大小：294K
• 年卷期：v.14,no.22(November 16, 2012)
• ISSN：1523-7052

文摘

The first heteroatom-based dienophile cycloadditions to cross-conjugated alkenes ([n]dendralenes) are reported. Nitroso-dienophiles undergo smooth single and double Diels鈥揂lder additions to the parent dendralenes with orientational regio- and stereoselectivity and, notably, with reactivity that depends upon the parity of the [n]dendralene. The first crystal structure of a cross-conjugated hexaene is reported. Vasella鈥檚 nitroso-sugar reagent gives a highly enantiomerically enriched double cycloadduct with [3]dendralene. This bicyclic oxazine is successively dihydroxylated and then ring-opened to form a branched chain diamino tetrol.