(−)-(1R,2R,7S,8aR)-1,2,7-Trihydroxyindolizidine ((−)-7S-OH-Lentiginosine): Synthesis and Proapoptotic Activity
作者:Franca M. Cordero、Paola Bonanno、Bhushan B. Khairnar、Francesca Cardona、Alberto Brandi、Beatrice Macchi、Antonella Minutolo、Sandro Grelli、Antonio Mastino
DOI:10.1002/cplu.201100069
日期:2012.3
An improved approach for the preparation of enantiopure 3,4‐bis‐tert‐butoxypyrroline N‐oxides is presented. Etherification of 1‐benzylpyrrolidine‐3,4‐diol with tBuOAc/HClO4 and subsequent N‐debenzylation and pyrrolidine oxidation with oxone affords the cyclic nitrone reliably and in superior yield. The enantiomer derivedfrom D‐tartaricacid was exploited in a modified synthesis of (−)‐7S‐OH‐lentiginosine
提出了一种改进的制备对映体3,4-二叔丁氧基吡咯啉N-氧化物的方法。用t BuOAc / HClO 4对1-苄基吡咯烷-3,4-二醇进行醚化反应,随后进行N-脱苄基化反应和吡咯烷氧化并用氧杂环丁烷进行氧化,可可靠地提供环硝酮,并具有较高的收率。衍生自D-酒石酸的对映体被用于(-)-7 S -OH-lentiginosine的改良合成中。检验了这种三羟基吲哚并咪唑在诱导淋巴样和上皮来源的肿瘤细胞系凋亡中的活性。
Synthesis of the New 7<i>S</i>-Aminolentiginosine and Derivatives
作者:Franca M. Cordero、Paola Bonanno、Sven Neudeck、Carolina Vurchio、Alberto Brandi
DOI:10.1002/adsc.200800806
日期:2009.5
Abstractmagnified imageThe new 7S‐aminolentiginosine has been synthesized by a diastereoselective 1,3‐dipolar cycloaddition strategy starting from 3,4‐dihydroxylated pyrroline N‐oxides derived from L‐tartaric acid in thirteen steps. The intermediate 7S‐azidolentiginosine undergoes efficiently copper(I)‐catalysed Huisgen cycloadditions to alkynes.
Synthesis of polyhydroxyindolizidines from 5,6-dihydro-2H-pyran-2-one
o-pyrrolidino[1,2-b]isoxazolidino[4,5-c]tetrahydropyran (8) prepared by (1,3)-dipolar cycloaddition of the cyclicnitrone6 derived from tartaric acid to 5,6-dihydro-2H-pyran-2-one (7) was transformed into indolizidine 11 via a sequence of reactions involving methanolysis of the lactone ring, intramolecular alkylation of the nitrogen atom promoted by a carbontetrabromide-triphenylphosphine mixture
(+)-Lentiginosine (14) and (7R)-7-hydroxylentiginosine (26), powerful inhibitors of amyloglucosidases, and their enantiomers were obtained in high overall yields by a multistep synthesis involving 1,3-dipolar cycloaddition of enantiopure tartaric acid derived pyrroline N-oxides. Structurally related (S,S)-3,4-dihydroxypyrrolidines 29-33 were synthesized as simpler models and tested towards 24 glycosidases.