(S)-8-Benzyloxy-4-(3-hydroxy-propoxy)-8,9-dihydro-3H,7H-pyrrolo[3,2-f]quinoline-2,6-dicarboxylic acid dimethyl ester

(S)-4-(3-Acetoxy-propoxy)-8-benzyloxy-8,9-dihydro-3H,7H-pyrrolo[3,2-f]quinoline-2,6-dicarboxylic acid dimethyl ester

7-(3-Acetoxy-propoxy)-4-((S)-2-benzyloxy-3-hydroxy-propyl)-5-methoxycarbonylamino-1H-indole-2-carboxylic acid methyl ester

7-(3-Acetoxy-propoxy)-4-((S)-2,3-bis-benzyloxy-propyl)-1H-indole-2,5-dicarboxylic acid 2-methyl ester

4-((S)-2,3-Bis-benzyloxy-propyl)-7-(3-hydroxy-propoxy)-1H-indole-2,5-dicarboxylic acid 5-benzyl ester 2-methyl ester