合成路线1

The condensation of allylmalonic acid diethyl ester (I) with 2-methoxyethyl bromide (II) by means of NaOEt in ethanol gives 2-allyl-2-(2-methoxyethyl)malonic acid diethyl ester (III), which is monodecarboxylated with LiCl in DMSO/DMF at 170 C to yield the pentenoic ester (IV). The reduction of the ester group of (IV) with LiAlH4 in dry ether affords the alcohol (V), which is oxidized to the corresponding aldehyde (VI) with (COCl)2 in dichloromethane. The protection of the aldehyde group of (VI) with ethyleneglycol (VII) and Ts-OH affords the cyclic ketal (VIII), which is treated with BH3/Me2S in dichloromethane to provide the primary alcohol (IX). The oxidation of (IX) with (COCl)2 as before gives the corresponding aldehyde (X), which is condensed with the indoloazepine (XI) in refluxing toluene, yielding the pyrrolocarbazole derivative (XII). The reductive ring opening of (XII) with NaBH4 in hot acetic acid affords the tricyclic intermediate (XIII), which is debenzylated with H2 over Pd/C in acetic acid to provide the secondary amine (XIV). The deprotection of the cyclic ketal group of (XIV) with HCl and HOAc, followed by treatment with NaOH, induces cyclization to the tetracyclic compound (XV), which is finally cyclized to the target compound in refluxing toluene.