Beyond optical rotation: what's left is not always right in total synthesis†,Chemical Science

当前位置： X-MOL 学术 › Chem. Sci. › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Beyond optical rotation: what's left is not always right in total synthesis†
Chemical Science ( IF 7.6 ) Pub Date : 2017-10-30 00:00:00 , DOI: 10.1039/c7sc04249c
Leo A Joyce ₁ , Christopher C Nawrat ₁ , Edward C Sherer ₂ , Mirlinda Biba ₁ , Andrew Brunskill ₁ , Gary E Martin ₁ , Ryan D Cohen ₁ , Ian W Davies ₁

Affiliation

This work describes the application of vibrational (VCD) and electronic (ECD) circular dichroism spectroscopy to solve the longstanding debate around the absolute configuration of (+)-frondosin B (1). The absolute configuration of (+)-1 could confidently be assigned as (R) using these spectroscopic techniques. The discrepancy in the optical rotation (OR) values obtained in previous studies can be attributed to an undetected minor impurity (ca. 7%) that arose unexpectedly in a key step late in the synthesis. Additionally, the conditions used in the final step of the previous reports for demethylation to form the natural product proceeded with significant loss of enantiopurity. The large OR measured for the impurity at its observed level, when compared to the small rotation for the less enantiopure natural product 1, led to a measured OR value for the synthetic material that had the opposite sign of the natural product.

中文翻译：

超越旋光：全合成中剩下的并不总是正确的†

这项工作描述了振动 (VCD) 和电子 (ECD) 圆二色光谱的应用，以解决围绕 (+)-叶叶素 B 绝对构型的长期争论 ( 1 )。使用这些光谱技术可以放心地将 (+)- 1的绝对构型指定为 ( R )。先前研究中获得的旋光度 (OR) 值的差异可归因于合成后期关键步骤中意外出现的未检测到的微量杂质（约7%）。此外，先前报道的去甲基化形成天然产物的最后步骤中使用的条件会导致对映体纯度的显着损失。当与对映体纯度较低的天然产物1的小旋转相比时，在其观察水平上测量的杂质的大OR值导致合成材料的测量OR值具有与天然产物相反的符号。

更新日期：2017-10-30

点击分享查看原文

点击收藏

公开下载

阅读更多本刊最新论文本刊介绍/投稿指南11