| Popis: |
The enantiospecific total synthesis of (+)-3-epi-epohelmin was accomplished by rapid construction of the pyrrolizidine core starting from enantiopure L-pyrroglutamic acid. The key reaction included a highly regio-and stereoselective intramolecular cyclopropanation reaction, regioselective ring opening of a nitrogen-substituted donor-acceptor cyclopropane, stereoselective reduction of a ketone, chemoselective organolithium addition to a Weinreb amide, and chemoselective oxidation of an allylic alcohol. |
