合成路线1

Maleimide (I) was brominated in the presence of benzoyl peroxide to give 3,4-dibromomaleimide (II). Alkylation of (II) with 4-(tert-butyl)benzyl bromide (III) in the presence of potassium carbonate afforded the N-(tert-butylbenzyl) derivative (IV). Coupling of the dibromomaleimide (IV) with the indolylmagnesium iodide resulting from 5-fluoroindole (V) and MeMgI furnished the bis-indolyl maleimide (VI). Oxidative cyclization of (VI) using dicyanodichlorobenzoquinone yielded the target indolopyrrolocarbazole system (VIII). Glycosylation of (VIII) with the protected fluoro glucose derivative (VIII) under Mitsunobu conditions afforded adduct (IX). The O-benzyl protecting groups were then removed by transfer hydrogenation with cyclohexene and Pd(OH)2 to give (X). The tert-butylbenzyl group was finally removed by basic hydrolysis followed by recyclization with fused ammonium acetate.