The reaction of C60 with pregnen-20-carboxaldehyde, a biologically active synthetic steroid, by using a 1,3-dipolar cycloaddition reaction (Prato's protocol) results in the formation of pyrrolidine rings bearing a new stereogenic center on the C2 of the five-membered ring. The formation of the fullerene-steroid hybrids proceeds with preference for the Re face of the 1,3-dipole, with formation of a diastereomeric mixture in 73:15 ratio. The investigation of the chiroptical properties of these conjugates allowed determining the absolute configuration of the new fulleropyrrolidines. In addition, a thorough spectroscopical study permitted to determine the structure of the two mono-cycloadducts. The electrochemical properties of the new hybrids were also evaluated by cyclic voltammetry, both systems exhibit three quasi-reversible reduction waves which are cathodically shifted in regard to the parent C60. Theoretical calculations help supporting the experimental data. A conformational study combining semiempirical methods and density functional theory has predicted the most stable diastereomer. On the basis of this agreement, a possible reaction mechanism is presented. Additionally, a molecular docking simulation has been carried out using the HIV-1 protease as receptor, thus paving the way to study the possible application of these stereoisomers in biomedicine.

中文翻译：

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类固醇-[60]富勒烯杂化物的非对映选择性合成及理论基础。

C60与pregnen-20-甲醛（一种生物活性合成类固醇）的反应通过1,3-偶极环加成反应（Prato规程）导致吡咯烷环的形成，该环在5个碳原子的C2上带有新的立体中心成员环。富勒烯-类固醇杂化物的形成优先于1，3-偶极的Re面，并且以73:15的比例形成非对映异构体混合物。对这些缀合物的手性的研究使得可以确定新的全吡咯烷的绝对构型。此外，通过彻底的光谱研究可以确定两个单环加合物的结构。还通过循环伏安法评估了新杂化物的电化学性能，这两个系统都表现出三个准可逆的还原波，它们相对于母体C60发生了阴极移位。理论计算有助于支持实验数据。结合半经验方法和密度泛函理论的构象研究预测了最稳定的非对映异构体。在此协议的基础上，提出了一种可能的反应机理。此外，已经使用HIV-1蛋白酶作为受体进行了分子对接模拟，从而为研究这些立体异构体在生物医学中的可能应用铺平了道路。在此协议的基础上，提出了一种可能的反应机理。此外，已经使用HIV-1蛋白酶作为受体进行了分子对接模拟，从而为研究这些立体异构体在生物医学中的可能应用铺平了道路。在此协议的基础上，提出了一种可能的反应机理。此外，已经使用HIV-1蛋白酶作为受体进行了分子对接模拟，从而为研究这些立体异构体在生物医学中的可能应用铺平了道路。