Highly Diastereoselective Additions to Polyhydroxylated Pyrrolidine Cyclic Imines: Ready Elaboration of Aza-Sugar Scaffolds To Create Diverse Carbohydrate-Processing Enzyme Probes
作者:Timothy M. Chapman、Steve Courtney、Phil Hay、Benjamin G. Davis
DOI:10.1002/chem.200304718
日期:2003.7.21
and threitol polyhydroxylated pyrrolidine imine scaffolds have been rapidly elaborated to diversely functionalized aza-sugars through highly diastereoselective organometallic (RM) additions (R=Me, Et, allyl, hexenyl, Ph, Bn, pMeO-Bn). The yields for these additions have all been substantially enhanced from previously optimised levels (<58 %) for normal additions using a reverse addition procedure (e
通过高度非对映选择性有机金属(RM)添加(R=Me、Et、烯丙基、己烯基、Ph、Bn、pMeO-Bn),代表性的非对映异构体、赤藓糖醇和苏糖醇多羟基化吡咯烷亚胺支架已被快速制备成多种功能化的氮杂糖。这些添加的产率均已从先前使用反向添加程序(例如 R=Ph;44% 正常模式 --> 78% 反向模式)的正常添加的优化水平(<58%)显着提高。高非对映选择性(除 R = Me 外,所有的均 > 98 % de)与受与偶氮甲亚胺碳相邻的 C-2 中心的构型和吡咯烷亚胺的构象控制的添加相一致。1-epi-和 2-epi-去乙酰茴香霉素的简明合成证明了该方法的高潜力。此外,这种亚胺添加方法允许在后期添加疏水性取代基,从而能够制备具有增强抑制潜力的新型氮杂糖。通过针对 12 种非哺乳动物和人类碳水化合物加工酶的不同小组筛选这些“疏水改性”氮杂糖的代表性选择来突出这一点。这确定了一种新型纳摩尔 α-半乳糖苷酶抑制剂