[Indole cleavage with mebhydroline by sodium periodate--part 2. Mechanism of the dilactam formation].
The gamma-carbolines 1a-d reacted with periodate by loss of one carbon--without available precursors to the eight-membered dilactams 3a-c and the amino acid 9d. As possible intermediates of an indole cleavage alpha-aminoketones as models were examined. While the oxidation of chain-formed 13 afforded only a small amount of C-lost amide 23, the cyclic species 24 and 32 gave rise to considerably higher yields of the corresponding lactams 29 and 36. From the benzazepinone 32 with Hg(II)-EDTA the intermediate product 43, containing all genuine C-atoms, was formed, which could quantitatively cleaved by periodate to the lactam 36 and formic acid. This mechanism can be transferred to the reactions of the gamma-carbolines 1a-d.
Möhrle
H
H
Institut für Pharmazeutische Chemie, Heinrich-Heine-Universität, Düsseldorf, Germany. h.moehrle@uni-duessldorf.de
Rohn
C
C
Westle
G
G
D002243:Carbolines / Q000737:chemistry*; D002849:Chromatography, Gas; D003500:Cyclization; D005561:Formates / Q000737:chemistry; D007202:Indicators and Reagents; D007211:Indoles / Q000737:chemistry*; D007769:Lactams / Q000138:chemical synthesis*; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D010084:Oxidation-Reduction; D010504:Periodic Acid / Q000737:chemistry*; D013055:Spectrophotometry, Infrared
D002243:Carbolines; D005561:Formates; D007202:Indicators and Reagents; D007211:Indoles; D007769:Lactams; C030544:formic acid; D010504:Periodic Acid; C005139:mebhydroline; C009288:metaperiodate