A simple procedure for the synthesis of (poly)cyclic O,O- and N,O-acetals from various enol ethers, N-acyl enamines or Boc-protected enamines has been developed. The key step is a photocatalytic Stork–Ueno-type cylization using the very simple metal-free conditions of catalytic eosin, diisopropylamine in the green solvent ethanol with blue LED irradition.

中文翻译：

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曙红、蓝色 LED 和 DIPEA 用于（多）环 O,O- 和 N,O-缩醛的简单合成

已经开发出一种从各种烯醇醚、N-酰基烯胺或 Boc 保护的烯胺合成（多）环O、O-和N , O-缩醛的简单方法。关键步骤是在绿色溶剂乙醇中使用非常简单的无金属催化条件曙红、二异丙胺和蓝色 LED 照射进行光催化 Stork-Ueno 型环化。