Ring-Opening Reactions of Cyclic Acetals and 1,3-Oxazolidines with Halosilane Equivalents
作者:Arihiro Iwata、Heqing Tang、Atsutaka Kunai、Joji Ohshita、Yasushi Yamamoto、Chinami Matui
DOI:10.1021/jo020019f
日期:2002.7.1
Similarly, the C-O bond of 1,3-oxazolidine rings cleaved to give ring-opened imine or enamine derivatives. The reactions of aromatic ketone ethylene acetals and cyclohexanone trimethylene acetal led to deprotection of the acetal unit to liberate free ketones. With reagent 1b, cycloalkanone ethylene acetal afforded a dimeric product with 2-iodoethyl alkenoate moieties, while aromatic ketone ethylene
使用两种碘硅烷等效试剂检查了乙缩醛和1,3-恶唑烷环的反应:Me3SiNEt2和MeI的1:2混合物(试剂1a)和Et3SiH和MeI的1:1混合物,其中含有催化量的PdCl2(试剂1b)。在链烷酮乙烯缩醛与试剂1a的反应中,缩醛环中的CO键容易断裂,得到2-(三甲基甲硅烷氧基)乙基烯醇醚。类似地,将1,3-恶唑烷环的CO键裂解,得到开环的亚胺或烯胺衍生物。芳族酮乙缩醛和环己酮三亚甲基缩醛的反应导致缩醛单元脱保护以释放出游离酮。用试剂1b,环烷酮乙烯缩醛得到具有2-碘乙基链烯酸酯部分的二聚产物,而芳族酮乙烯或三亚甲基缩醛产生脱保护的酮。