合成路线1

The reduction of diethyl 3-(methoxymethoxy)glutarate (I) with LiAlH4 in THF gives 3-(methoxymethoxy)pentane-1,5-diol (II), which is treated with Ts-OH and TEA in THF to yield the disulfonate (III). The condensation of (III) with 5-ethoxyindolin-2-one (IV) by means of tBu-OK in THF affords the spiro compound (V), which is deprotected with HCl in methanol to afford the spiranic alcohol (VI). The oxidation of (VI) with pyridinium chlorochromate (PCC) over Al2O3 provides the spiranic cyclohexanone (VII), which is treated with 2-chloroethanol (VIII) and Ms-OH in toluene to give the ketal (IX). The reaction of (IX) with zinc borohydride and trimethylsilyl chloride in ethyl ether/dichloromethane yields the 2-chloroethoxy derivative (X), which is condensed with 4-(N-tert-butylcarbamoyl)-2-methoxybenzenesulfonyl chloride (XI) by means of tBu-OK in THF to afford the adduct (XII). Finally, the target compound is obtained by condensation of (XII) with morpholine (XIII) by means of NaI in DMF, followed by treatment with fumaric acid.