Despite the biological interest in chromane derivatives, few studies dedicated to the functionalisation of this heterocycle have been reported. Herein, our objective is to demonstrate the potential of alkali metal bases for the introduction of substituents at its positions 4 and 8, and to explain the observed reactivity based on quantum chemical calculations. Guided by these theoretical results, preliminary optimisation was carried out on 2,3‐dihydrobenzofuran before applying the optimal conditions to chromane. Deprotolithiation at C8 was thus achieved using n‐butyllithium in hexane at room temperature, while functionalisation at C4 was promoted by a 1:1 mixture of lithium 2,2,6,6‐tetramethylpiperidide and potassium tert‐butoxide in tetrahydrofuran at ‐50 °C. Various electrophiles were used to intercept the lithiated intermediates, providing a convenient access to substituted chromane derivatives.

中文翻译：

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通过去质子金属化对色满进行官能化


尽管人们对苯并二氢吡喃衍生物具有生物学兴趣，但很少有专门针对这种杂环化合物功能化的研究报道。在此，我们的目标是证明碱金属碱在 4 和 8 位引入取代基的潜力，并基于量子化学计算解释观察到的反应性。在这些理论结果的指导下，在将最佳条件应用于苯并二氢吡喃之前，对2,3-二氢苯并呋喃进行了初步优化。因此，在室温下，使用己烷中的正丁基锂在室温下实现了 C8 的去原锂化，而在 ‐50 ° 下，通过 2,2,6,6-四甲基哌啶锂和叔丁醇钾在四氢呋喃中的 1:1 混合物促进了 C4 的官能化。 C。使用各种亲电子试剂来拦截锂化中间体，从而方便地获得取代的苯并二氢吡喃衍生物。