Indolalkaloide, II. – Synthese von 4-Amino-tetrahydrocarbazol-1-on-Derivaten
Indole Alkaloids, II. – Synthesis of 4-Amino-tetrahydrocarbazol-1-one Derivatives 
 
 
 
Treatment of 1,2,3,4-tetrahydrocarbazol-1-one with 1,2-ethanedithiol gave the tetrahydrocarbazole 2 which was oxidized with DDQ to compound 3. It was converted into the imine 6 by treatment with n-butylamine and ZnCl2. The imine was directly reduced with NaBH4 to give the amine 7, which was acetylated with benzoyl chloride to yield amide 8. Treatment of 8 with mercury(II) oxide and Et2O·BF3 gave 9.