Ring expansive routes to quinolizidine alkaloids: formal synthesis of (-)-lasubine II.
The application of two nitrogen ring expansion reactions to lasubine alkaloid synthesis is reported. The approach involves a conjugate reduction/alkylation sequence carried out on triisopropylsilyl-protected (S)-4-(-)-hydroxycyclopentenone, the formation of the quinolizidone ring system through nitrogen ring expansion, and the addition of an arylmetallic species to the resulting lactam. This work resulted in the preparation of 2-epi-lasubine II and a formal synthesis of lasubine II. [reaction: see text]
Gracias
Vijaya
V
Department of Medicinal Chemistry, 1251 Wescoe Hall Drive, Room 4070, Malott Hall, University of Kansas, Lawrence, KS 66045-7582, USA.
Zeng
Yibin
Y
Desai
Pankaj
P
Aubé
Jeffrey
J
D000470:Alkaloids / Q000138:chemical synthesis*; D000478:Alkylation; D031563:Lagerstroemia / Q000737:chemistry; D018515:Plant Leaves / Q000737:chemistry; D011807:Quinolizines / Q000138:chemical synthesis*
D000470:Alkaloids; D011807:Quinolizines; C414385:lasubin I