Regiochemical control of the ring opening of 1,2-epoxides by means of chelating processes. 8. Synthesis and ring opening reactions of cis- and trans- oxides derived from 3-benzyloxycyclohexene and 2-benzyloxy-5,6-dihydro-2H-pyran
作者:Federico Calvani、Paolo Crotti、Cristina Gardelli、Mauro Pineschi
DOI:10.1016/s0040-4020(01)81219-9
日期:1994.1
The regiochemical outcome of the ring opening of 1,2-epoxides bearing polar remote functionalization through chelation processes assisted by metal ions, was verified in cyclic oxirane systems having the polar functionality in an allylic position to the oxirane ring. The diastereoisomeric cis/trans epoxide pairs 5,6 and 7,8 derived from 3-benzyloxycyclohexene, and 2-benzyloxy-5,6-dihydro-2H-pyran, respectively
在具有在环氧乙烷环的烯丙基位置上具有极性官能团的环状环氧乙烷体系中,证实了通过金属离子辅助的螯合过程通过极性远程官能化而带有极性远程官能化的1,2-环氧化物的开环的区域化学结果。非对映体顺式/反式环氧化物对5,6和7,8由3- benzyloxycyclohexene衍生,和2-苄氧基- 5,6-二氢-2 H ^ -吡喃,分别制备和几个其开口的反应进行了研究。观察到的区域选择性在很大程度上取决于反应条件(标准条件或金属辅助条件),并且有趣地取决于所用亲核试剂的性质。