Regioselective Mitsunobu Reaction of Partially Protected Uridine

Mitsunobu reaction of partially acylated uridine proceeds with high regioselectivity for intramolecular S_N2 anhydro linkage closuring. Under the reaction conditions, an isomeric mixture of diacyl uridine derivatives with either free 2′- or 3′-hydroxyl group was transformed into a single cyclonucleosidic product, 2,2′-anhydro-3′,5′-di-O-acyluridine. This paper presents a possible mechanism of the reactions, the explanation of observed phenomenon based on semiempirical and density functional theory (DFT) calculations and possible utility of this synthetic pathway.

部分酰化尿苷的光延反应（Mitsunobu reaction）在进行分子内S_N2型脱水键环合时，表现出高区域选择性。在该反应条件下，带有游离2′-羟基或3′-羟基的二酰基尿苷衍生物异构体混合物，可被转化为单一的环核苷产物2,2′-脱水-3′,5′-二-O-酰基尿苷。本文阐述了该反应的可能机理、基于半经验方法与密度泛函理论（DFT）计算对观测到的实验现象的合理解释，以及该合成路径的潜在应用价值。