Total synthesis of the putative structure of stemonidine: the definitive proof of misassignment.
[structure: see text] The total synthesis of the putative structure of the Stemona alkaloid stemonidine has been completed. The key transformations include a 1,3-dipolar cycloaddition of a chiral nitrone derived from (S)-prolinol and a spirolactonization process involving the generation of the critical stereocenter. The NMR data of the synthetic material do not match those reported for the natural product. It is concluded that the structure assigned to stemonidine is incorrect, and it must be reassigned as stemospironine.
Sánchez-Izquierdo
Francisco
F
Universitat Autonoma de Barcelona, Departament de Química, 08193 Bellaterra, Spain.
Blanco
Pilar
P
Busqué
Félix
F
Alibés
Ramón
R
de March
Pedro
P
Figueredo
Marta
M
Font
Josep
J
Parella
Teodor
T
D000470:Alkaloids / Q000737:chemistry; D001372:Aza Compounds / Q000737:chemistry; D006573:Heterocyclic Compounds, 1-Ring / Q000737:chemistry; D007783:Lactones / Q000138:chemical synthesis* / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D009589:Nitrogen Oxides / Q000737:chemistry; D009930:Organic Chemicals / Q000138:chemical synthesis* / Q000737:chemistry; D011759:Pyrrolidines / Q000138:chemical synthesis* / Q000737:chemistry; D013141:Spiro Compounds / Q000138:chemical synthesis* / Q000737:chemistry
D000470:Alkaloids; D001372:Aza Compounds; D006573:Heterocyclic Compounds, 1-Ring; D007783:Lactones; D009589:Nitrogen Oxides; D009930:Organic Chemicals; D011759:Pyrrolidines; D013141:Spiro Compounds; C015388:nitrones; C520152:stemonidine; C010509:prolinol