Synthesis of New Hydroxybenzo[a]carbazoles

Abstract

An investigation of the alkylation sites of 4,7-dihydroxybenzo[a]pyrrolo[3,4-c]carbazole-1,3(2H,8H)-dione, as well as the site of reduction in the maleimide upper ring, was carried out which resulted in the synthesis of diversely substituted 4-hydroxybenzo[a]pyrrolo[3,4-c]carbazoles. Moreover, the synthesis of 5,6-dicyano-1,4-dihydroxy-11H-benzo[a]carbazole was performed in which the maleimide ring of the above scaffold is missing and is replaced by electron-withdrawing nitrile groups.

Total synthesis of (−)-amathaspiramide A via a one-pot aldol addition/transamidification reaction

“…The reason for more carbonyl reduction products being obtained at C-6 might be due to the fact that the coordination of the tertiary amine on N-1 of our substrate with aluminium was difficult in spite of the presence of Al(Oi-Pr) 3 . LiAlH 4 , 16 NaBH 4 , 17 L-selectride, 18 and other reducing agents 9b,19 were also screened, but the desired product was not obtained (see the ESI †).…”