Stereoselective Synthesis of Substituted Oxocene Cores by Lewis Acid Promoted Cyclization

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• 作者：Arun K. Ghosh ; Anthony J. Tomaine ; Kelsey E. Cantwell
• 刊名：Organic Letters
• 出版年：2016
• 出版时间：February 5, 2016
• 年：2016
• 卷：18
• 期：3
• 页码：396-399
• 全文大小：328K
• ISSN：1523-7052

文摘

Substituted oxocene derivatives have been synthesized by Lewis acid catalyzed reactions of ε-hydroxyalkene and substituted aromatic aldehydes. The Cu(OTf)₂-bis-phosphine catalyzed reaction typically provides substituted dihydropyran derivatives through an olefin migration followed by a Prins cyclization. The corresponding reaction catalyzed by TMSOTf or BF₃·OEt₂ provided eight-membered cyclic ethers (oxocenes), selectively. This methodology provides convenient access to a variety of 2,4,8-trisubstituted oxocenes in good yields and excellent diastereoselectivities.