Formal Total Synthesis of Enantiopure Tricyclic (S)-Myrmicarin Alkaloids 217, 215A and 215B
摘要:
We described herein a formal synthesis of the enantiopure tricyclic (4aS)-myrmicarin alkaloids 217, 215A and 215B owing to the obtention of a common pyrroloindolizidine intermediate, starting from a chiral cis-(2S,5R)-disubstitated pyrrolidine. An intramolecular one-pot aldolization-crotonization-aromatization process of a diketo indolizidine constitutes the key step for the formation of the pyrrole ring of the target compound.
We described herein a formal synthesis of the enantiopure tricyclic (4aS)-myrmicarin alkaloids 217, 215A and 215B owing to the obtention of a common pyrroloindolizidine intermediate, starting from a chiral cis-(2S,5R)-disubstitated pyrrolidine. An intramolecular one-pot aldolization-crotonization-aromatization process of a diketo indolizidine constitutes the key step for the formation of the pyrrole ring of the target compound.