Synthesis of the atropurpuran A-ring via an organocatalytic asymmetric intramolecular Michael addition
作者:Huan Chen、Dan Zhang、Fei Xue、Yong Qin
DOI:10.1016/j.tet.2013.02.078
日期:2013.4
The asymmetric synthesis of the A-ring fragment 2a–b of atropurpuran 1 has been achieved in 15 steps with up to 70% ee via an organocatalytic intramolecularMichaeladdition of nitroalkene 10. The absolute configuration of the two contiguous carbon centers in 2a and 2b was assigned to be (4S, 5R) and (4R, 5R), respectively, using the modified Mosher's method.