Alternative Methylation for the Synthesis of (+)-Perophoramidine
作者:Yu Du、Haoxing Wu、Hao Song、Yong Qin、Dan Zhang
DOI:10.1002/cjoc.201200295
日期:2012.9
An alternative N1‐methylation strategy was reported in the late‐stage of the total synthesis of (+)‐perophoramidine. Preparation of (+)‐perophoramidine was featured by an acid‐catalyzed isomerization of amidine 5 to its CN double bond tautomer 8, followed by two steps of N1‐methylation with NaHMDS/MeOTf and oxidation with MnO2. In contrast, direct methylation of amidine 5 afforded the N23‐methylation