A new one‐pot, two‐step silver‐catalyzed spiroketalization of the in‐situ generated quinone imine ketals (QIKs) with β‐alkynyl ketones has been established, enabling multiple C−O and C−C bond‐forming reactions to access densely functionalized spiro[benzofuran‐2,1′‐isochromene] derivatives with generally good yields. The use of β‐alkynyl ketones bearing alkyl and aryl groups located at the α‐position of the carbonyl group could lead to highly diastereoselective spiro[chromane‐2,1′‐isochromene] derivatives. The reaction features broad substrate scope, mild oxidative catalytic conditions and excellent diastereoselectivity.

中文翻译：

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氧化催化螺环化导致非对映选择性合成螺[苯并呋喃-2,1'-异戊二烯] s

已经建立了一种新的一锅，两步，银催化的带有β-炔基酮的原位生成的醌亚胺缩酮（QIKs）的螺环缩酮化反应，使多个C-O和C-C键形成反应能够密集地进行功能化的螺[苯并呋喃-2,1'-异戊二烯]衍生物，收率通常很高。使用位于羰基基团α-位带有烷基和芳基的β-炔基酮可能会导致非对映选择性的螺[chromane-2,1'-isochromene]衍生物。该反应具有广泛的底物范围，温和的氧化催化条件和出色的非对映选择性。