A new synthetic access to bicyclic polyhydroxylated alkaloid analogues from pyranosides
作者:Ning Wang、Li-He Zhang、Xin-Shan Ye
DOI:10.1039/b923180c
日期:——
A facile, versatile and stereoselective synthesis of bicyclic polyhydroxylated alkaloids as castanospermineanalogues is described. The synthetic route started from methyl pyranosides. The key steps involved a high-yielding expeditious one-pot tandem reaction from alkenes to N-substituted δ-lactams. The δ-lactams were stereoselectively vinylated to give the dienes, which were followed by the ring-closing
2-Hydroxycastanospermines (dihydroxy-L-swainsonines) from octonolactones: Inhibition of naringinase (L-rhamnosidase)
作者:Andrew A. Bell、Lea Pickering、Alison A. Watson、Robert J. Nash、Rhodri C. Griffiths、M.George Jones、George W.J. Fleet
DOI:10.1016/0040-4039(96)01956-9
日期:1996.11
ermine — in which there are 6 adjacent chiral centres and 8 contiguous carbon atoms containing functional groups from eight carbon sugar lactones — depend on efficient cyclisations to give piperidines with trans-acetonides as protecting groups. Inhibition of naringinase (L-rhamnosidase) by 2S-2-hydroxy-6-epicastanospermine and 2S-2-hydroxycastanospermine may be due to a structural resemblance to the
Synthesis of Pentahydroxy Indolizidine Alkaloids Using Ring Closing Metathesis: Attempts To Find the Correct Structure of Uniflorine A
作者:Narayan S. Karanjule、Shankar D. Markad、Dilip D. Dhavale
DOI:10.1021/jo060823s
日期:2006.8.1
Ring closing metathesis of d-glucose derived diene-substrate containing nitrogen functionality followed by asymmetric dihydroxylation afforded sugar substituted dihydroxylated pyrrolidines 8a−c which on 1,2-acetonide deprotection and reductive amination afforded putative uniflorine A 2a and its analogues 2b−c, respectively.