An Efficient and Large-Scale Enantioselective Synthesis of PNP405: A Purine Nucleoside Phosphorylase Inhibitor
作者:Mahavir Prashad、Denis Har、Lijian Chen、Hong-Yong Kim、Oljan Repič、Thomas J. Blacklock
DOI:10.1021/jo020256i
日期:2002.9.1
large-scale enantioselective synthesis of PNP405 (1), a purine nucleoside phosphorylase inhibitor, is described. This synthesis of 1 involved eight steps starting from o-fluorophenylacetic acid with a 21.6% overall yield and >99.5% enantiopurity. The key stereogenic center with (R)-configuration was created using Evans' asymmetric alkylation methodology. This synthesis also features the racemization-free
描述了一种嘌呤核苷磷酸化酶抑制剂PNP405(1)的高效,大规模对映选择性合成。1的合成涉及从邻氟苯基乙酸开始的八个步骤,总产率为21.6%,对映体纯度为99.5%。使用Evans的不对称烷基化方法创建了具有(R)-构型的关键立体异构中心。该合成还具有以下特征:使用硼氢化钠可无消旋地还原5中的手性助剂,通过新的水辅助三苯甲基与三苯甲基氯和三乙胺或三苯甲醇与催化作用的三苯甲基化反应,保护γ-氰醇6作为三苯甲基醚。三氟乙酸,以及使用氰酰胺作为胍基化剂的高效一锅式10环胍基化。