Studies toward Australifungin. A Synthesis Dilemma of Regioselective Keto–Enol Tautomerization

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• 作者：David R. Williams ; J. Cullen Klein ; Lucas C. Kopel ; Nhu Nguyen ; Dean J. Tantillo
• 刊名：Organic Letters
• 出版年：2016
• 出版时间：February 5, 2016
• 年：2016
• 卷：18
• 期：3
• 页码：424-427
• 全文大小：355K
• ISSN：1523-7052

文摘

Studies have advanced a stereocontrolled pathway for the synthesis of australifungin. Elaboration of the trans-fused IMDA product 4 led to the cis-diol 15, which produced the α-hydroxyenone 19 upon oxidation. Computational studies on model systems indicate that the keto–enol tautomer shown for 19 is higher in energy than the keto–enol tautomer represented by the natural product 1. The reactivity of 19 does not permit mild isomerization and subsequent deprotection to yield 1. These findings raise new questions regarding the synthesis and bioactivity of australifungin and related natural products.