- Diterpenoid alkaloids from aconitum episcopale
-
Three new diterpenoid alkaloids, liaconitine A (N-ethyl- 1α,6α,16β,18-tetramethoxy-13β-ol-2,3-dehydroaconitane-8-acetate-14- anisoylate), B (N-ethyl- 1α,6α, 16β,18-tetramethoxy- 13β-ol-2,3- dehydroaconitane-8,14-dianisoylate and C (N-ethyl- 1α,6α,16β,18- tetramethoxy-8-ethoxy-13β-ol-2,3-dehydroaconitane-14-anisoylate) have been isolated from the roots of Aconitum episcopale. The structures of the new compounds were established by spectroscopic methods and reduction of liaconitine A to the known alkaloid, crassicauline A.
- Yang, Jing-Hua,Li, Zi-Yan,Li, Liang,Wang, Yun-Song
-
-
Read Online
- DEOXYGENATION REACTIONS OF C19-DITERPENOID ALKALOIDS
-
Efficient methods for deoxygenation of secondary and tertiary alcohols of some C19-diterpenoid alkaloids are presented.Delphisine (12) was converted to 1-deoxydelphisine (19) via either 1,2-pyrodelphisine (17) or phenyl thionocarbonate 20.The following alkaloids were deoxygenated via their thiocarbonylimidazolyl derivatives: 14-acetyldelcosine (13) to 14-acetyl-1-deoxydelcosine (22); alkaline hydrolysis of 22 gave 1-deoxydelcosine (23); aconitine (24) to 3-deoxyaconitine (27); yunaconitine (25) to crassicauline A (28).Deoxygenation of 14-acetyldictyocarpine (30) via the chloro-derivate 31 gave 14-acetyl-10-deoxydictiocarpine (34).Reduction of 31 with LiAlH4 gave the unusual elimination product 32.An improved partial synthesis of hypaconitine (35) from aconitine (24) is also presented.
- Kulanthaivel, Palaniappan,Pelletier, S. William
-
p. 4313 - 4320
(2007/10/02)
-
