合成路线1

Oxidation of N-Boc-D-prolinol (I) with pyridinium dichromate affords aldehyde (II). This is subjected to Wittig condensation with methylene triphenylphosphorane to furnish N-Boc-2-vinylpyrrolidine (III). Hydroboration of (III) with 9-borabicyclononane, followed by oxidative work-up, leads to the primary alcohol (IV). Subsequent acidic Boc group cleavage in (IV) provides 2-pyrrolidinyl ethanol (V). Acylation of amine (V) with 4-methyl-3-nitrobenzenesulfonyl chloride (VI) gives sulfonamide (VII). The hydroxyl group of (VII) is further protected with methoxymethyl chloride, producing the methoxymethyl ether (VIII). Conversion of the ortho-nitrotoluene system (VIII) into indole (X) is then accomplished according to the Leimgruber-Batcho procedure, by condensation of (VIII) with dimethylformamide dimethylacetal, followed by reduction of the resultant nitro enamine (IX) with hydrazine in the presence of Raney nickel. Protection of the indole N of (X) with benzenesulfonyl chloride and NaH affords sulfonamide (XI). After acidic hydrolysis of the methoxymethyl protecting group of (XI), the N-phenylsulfonyl group is removed under alkaline conditions to yield indole (XII)