合成路线1

Alternatively, compound (XV) can also be obtained as follows: Reduction of (S)-maleate (XVI) with BMS-NaBH4 in THF, followed by O-protection with TBDPS-Cl and imidazole, yields alcohol (XVII), which is first allylated with allyl trichloroacetimidate (XVIII) catalyzed by triflic acid in cyclohexanes and then reduced with DIBAL in THF to provide compound (XIX). Ozonolysis of (XIX) in MeOH, followed by reductive quench with NaBH4, gives diol (XX), which is then converted into bismesylate (XXI) by treatment with MsCl and Et3N in ether. Compound (XXI) is subjected to a double Finkelstein reaction with NaI in acetone in the presence of NaHCO3 to yield bisiodide (XXII) (1), which is then coupled with 3-bis(1H-indol-3-yl)-N-methylmaleimide (XI) by means of Cs2CO3 in DMF to give intermediate (XV).