Nucleosides. Part LIX. The 2-(4-nitrophenyl)ethylsulfonyl (Npes) Group: A New Type of Protection in Nucleoside Chemistry
作者:Magdalena Pfister、Helga Schirmeister、Marion Mohr、Silke Farkas、Klaus-Peter Stengele、Tilman Reiner、Martin Dunkel、Surendra Gokhale、Ramamurthy Charubala、Wolfgang Pfleiderer
DOI:10.1002/hlca.19950780706
日期:1995.11.1
The 2-(4-nitrophenyl)ethylsulfonyl (npes) group is developed as a new sugar OH-blocking group in the ribonucleoside series. Its cleavage can be performed in a β-eliminating process under aprotic conditions using 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) as the most effective base. Since sulfonates do not show acyl migration, partial protection of 1,2-cis-diol moieties is possible leading to new types
2-(4-硝基苯基)乙基磺酰基(npes)基团被开发为核糖核苷系列中新的糖OH封闭基团。可以在非质子条件下以β-消除过程进行裂解,使用1,8-二氮杂双环[5.4.0]十一碳-7-烯(DBU)作为最有效的碱基。由于磺酸盐不显示酰基迁移,因此可能会部分保护1,2-顺式-二醇部分,从而导致新型的寡核苷酸构建基团。一系列由Markiewicz保护的核糖核苷1-10转化为它们的2'- O- [2-(4-硝基苯基)乙基磺酰基]衍生物29-38,其中5'-OSi键可通过酸水解裂解形成39- 45。随后的单甲氧基三苯甲基化导致46-50,和脱甲硅基,得到5'- ø - (单甲氧)-2'- ö - [2-(4-硝基苯基)乙基磺酰基]核糖核苷51-55。酸处理去除三苯甲基也不会伤害npes组(56-58)。完全封闭的2'- O- [2-(4-硝基苯基)乙基磺酰基]核糖核苷96-102的明确合成是通过相应的3'-