First Stereoselective Total Synthesis of Ligraminol E

摘要

Stereoselective total synthesis of Ligraminol E has been achieved in 8 steps in 23.9% overall yield by employing an imidazolidinone based chiral auxiliary. The key steps involved in the synthesis are the asymmetric glycolate alkylation of (R)-3-(2- (benzyloxy)acetyl)-4-isopropyl-1-((S)-1-phenylethyl)imidazo-lidin- 2-one with substituted benzyl bromide and the Mitsonobu reaction of a secondary alcohol and phenolic group.