Synthetic Approaches to Indolo[2,3-a]carbazole alkaloids. Syntheses of arcyriaflavin A and AT2433-B aglycone
摘要:
Ozonolysis of tetrahydrophthalimides 17 and 18 or cyclohexane diester 25 and treatment of the intermediate dialdehydes (19, 20, 26) with an arylhydrazine affords the corresponding bis-arylhydrazones (21-24, 27, 28). Exposure of 21 and 23 to PPSE in CH3NO2 gives the indolo[2,3-a]carbazole alkaloids arcyriaflavin A (8) and AT2433-B aglycone (29) in low yield. bis-Phenylhydrazones (osazones) (33, 34, 42, 44) of cyclohexandiones were synthesized by m-CPBA oxidation of 4,5-bis(trimethylsilyloxy)tetrahydrophthalimides followed by treatment of the presumed intermediate 1,2-cyclohexanediones with an arylhydrazine. These osazones were cyclized to the corresponding indolo[2,3-a]carbazoles with PPSE.
Fluorine-Containing Functionalized Cyclopentene Scaffolds Through Ring Contraction and Deoxofluorination of Various Substituted Cyclohexenes
作者:Attila Márió Remete、Melinda Nonn、Santos Fustero、Matti Haukka、Ferenc Fülöp、Loránd Kiss
DOI:10.1002/ejoc.201800057
日期:2018.8.1
The fluorination of some highly‐functionalized cyclopentene derivatives, obtained from various substituted cyclohexenes through a ring‐opening/ring‐contraction procedure, has been investigated. The transformations were found to be highly substrate dependent, and led to the formation of various functionalized alicyclic compounds or heterocycles containing allyl difluoride or vinyl fluoride moieties