合成路线1

The diastereo- and enantioselective condensation of the protected secondary amine (I) with the nitroalkene (II) by means of BuLi in toluene and in the presence of (-)-sparteine gives the (S,S)-carbamate (III) as a single diastereomer. The hydrolysis of the carbamate (III) with HCl in chloroform yields the aldehyde (IV), which is reduced with NaBH4, affording the alcohol (V). The reduction of the nitro group of (V) with Pd/C and ammonium formate gives the amine (VI), which is protected with Boc2O to provide the carbamate (VII). The reaction of (VII) with MsCl and TEA affords the corresponding mesylate (VIII), which is cyclized by means of potassium tert-butoxide in THF, yielding the protected piperidine (IX). Elimination of the Tips group of (IX) with TBAF affords the carbinol (X), which is treated with MsCl and TEA to give the mesylate (XI). The condensation of (XI) with 1,3-benzodioxol-5-ol (XII) by means of NaH in DMF yields the expected adduct (XIII), which is finally deprotected with TFA to furnish the target chiral compound.