formation of cyclopropanespiro-β-lactones. In contrast to most alkene cyclopropanations, including those involving diketene, the reaction occurs diastereoselectively. A computational model of the reaction has been developed that accounts for the observed stereochemistry. The metal promoted thermal rearrangement of these spiro compounds is also unusual in that it affords pyranones, rather than the decarboxylation
单取代的重氮酯和酮与4-[(Z)-亚乙基] -3-甲基氧杂
环丁烷-2-酮的
金属催化反应导致形成
环丙烷螺-β-内酯。与大多数烯烃
环丙烷化反应(包括涉及双烯酮的反应)相反,该反应是非对映选择性的。已经开发了解释所观察到的立体
化学的反应的计算模型。这些
螺环化合物的
金属促进的热重排也是不同寻常的,因为它提供
吡喃酮,而不是通常提供β-内酯的脱羧产物,或由双烯酮衍生的
环丙烷螺-β-内酯形成的
呋喃酮。