%0 Journal Article %T A NEW STRATEGY FOR THE SYNTHESIS OF TRICYCLIC AND TETRACYCLIC SYSTEMS OF INDOLE ALKALOIDS %J Journal of Sciences, Islamic Republic of Iran %I University of Tehran %Z 1016-1104 %D 2001 %\ 09/01/2001 %V 12 %N 3 %P - %! A NEW STRATEGY FOR THE SYNTHESIS OF TRICYCLIC AND TETRACYCLIC SYSTEMS OF INDOLE ALKALOIDS %R %X Reaction of tryptamine 1 with dimethyl -3-methoxyallylidenemalonate 2 afforded N?-[4,4-bis (methoxycarbonyl)-1,3-butadienyl] tryptamine 3 which in combination with acetylchloride and pyridine in dichloromethane gave N?, N?-[acetyl]-[(4,4-dinethoxycarbonyl) 1,3butadienyl] tryptamine 4. Treatment of 3 with sodium hydroxide afforded 2H[N-(3-indolyl) ethyl] 2-oxo-3-methoxycarbonyl-1-pyridine 5. Cyclization of 2 with trifluoroacetic acid gave methyl-2-(methoxycarbonyl) 4-(2,3,4,9-tetrahydro-1H-pyrido [3,4-b] indole-1-yle) butanoate 6. Heating of the latter in ethylacetate at reflux temperature afforded a new tetracyclic system methyl 4-oxo 1, 4, 6, 7, 12, 12b-hexahydro indolo [2, 3-a] quinolidine 3 carboxylate 7. %U https://jsciences.ut.ac.ir/article_31793_dd612f4d68d52c113b900f043c5b42da.pdf