Recent progress in the chemistry of indole alkaloids and mould metabolites

Synthesis of η6‐(4a‐Methyl‐1,2,3,4‐tetrahydro‐4aH‐carbazole)‐tricarbonylchromium complex and stereoelectronic behaviour with organolithium reagents: an apparent frontal attack to the (CO)3Cr group

“…Found: C,60.14;H,4.41;N, This compound has IR (KBr): 1935, 1850, 1590, 670, 625 cm -1 . 1 (5), 237 (100), 220 (11), 195 (10), 184 (7), 80 (15), 52 (90).…”

“…However, the same reaction in 2'-methylspiro[cyclohexan-1,3'-3Hindole] with methylmagnesium iodide gives the methyl insertion products on the 2'-methyl substituent in good yield, while the C=N addition product was not detected [4]. Reaction of 4a-methyl-1,2,3,4,-tetrahydro-1Hcarbazole (1) with organomagnesium halides in the presence of cuprous chloride gives only the cis-4a,9adialkylhexahydrocarbazole derivatives through a radicalic mechanism [5].…”

“…Alkaloids containing the cis-fused tetrahydrocarbazole system exhibit a considerable diversity of structure and a wide variety of biological activities [1]. Thus, derivatives of 4a-methyl-9a-substituted-1,2,3,4,4a,9a-hexahydrocarbazoles show a significant dopaminergic and serotoninergic activity [2a].…”

Recent progress in the chemistry of indole alkaloids and mould metabolites

“…A stereoselective synthesisl5, of the tetracyclic aminoketone (302) from L-tryptophan constitutes a formal synthesis of (-)koumine, ( -)-taberpsychine, and (-)-koumidine since the enantiomer of ( 302) is an important intermediate in the synthesis of the enantiomeric alkaloids by Magnus and his collaborators. 25 In an earlier i n v e s t i g a t i ~n , ~~ ajmaline was converted into the ring D norsarpagan derivative (303) in an attempt to achieve a partial synthesis of the gelsedine skeleton. Unfortunately, the oxidative rearrangement of (303) gave the oxindole (304), with !…”

“…Eight components have also been isolated from the roots of a second Murraya species not previously examined, namely M . siamensis Craib, the powdered root of which is said to be used in Thailand for the treatment of eye-sores, snakebite, and (24), 7-methoxymurrayacine (25), and 0-methylmukonal (3-formyl-2-methoxycarbazole, 26). The known alkaloids, heptaphylline, 7-methoxyheptaphylline, 2-hydroxy-3-formyl-7-methoxycarbazole, and mukonal, were also isolated, and the eighth constituent was a known coumarin, xanthoxyletin.…”