Synthesis of spirocyclic Δ4-isoxazolines via [3 + 2] cycloaddition of indanone-derived ketonitrones with alkynes
Yilin Liu1,2, Jiaxue Liu1, Yan-Yun Liu1
1Hunan Engineering Laboratory for Preparation Technology of Polyvinyl Alcohol (PVA) Fiber Material, Institute of Organic Synthesis, Huaihua University Huaihua 418000 China liuyilinhn@126.com liuyanyun314@sina.com.
Abstract:
A [3 + 2] cycloaddition of indanone-derived nitrones and alkynes under mild conditions is developed, allowing facile synthesis of spirocyclicindenyl isoxazolines with structural diversity. The sequential protocol of generated in situ ketonitrone from unsaturated ketones and N-alkylhydroxylamines is also achieved successfully, affording the desired products in considerable yield with moderate to good diastereoselectivity. Moreover, the spirocyclic product can be conveniently transformed into indenyl-based allylic alcohol and enamide.
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