合成路线1

N-Alkylation of benzyl N-allylcarbamate (I) with 5-bromo-1-pentene (II) by means of NaH in DMF provides olefin metathesis substrate (III), which is then converted into azepine (IV) by means of catalytic bis(tricyclohexylphosphine)benzylideneruthenium (IV) dichloride (Grubbs catalyst) in refluxing CH2Cl2. Epoxidation of (IV) with m-CPBA in CH2Cl2 affords oxirane (V), which is then treated with NaN3 and NH4Cl in H2O/MeOH to provide a mixture of regioisomers from which (VI) is chromatographically isolated. Reduction of azide (VI) with 1,3-propanedithiol and Et3N in MeOH furnishes amino alcohol derivative (VII), which is then acylated with Boc-Leu-OH by means of EDC and HOBt to provide protected derivative (IX). Removal of the Z protecting group by hydrogenolysis over Pd/C in MeOH gives amine (X), which is then condensed with 2-pyridylsulfonyl chloride (XI) by means of Et3N in CH2Cl2 to yield compound (XII). Boc removal from (XII) by treatment with HCl in MeOH/AcOEt affords amine (XIII), which is then acylated with benzofuran-2-carboxylic acid (XIV) by means of EDC and HOBt to give derivative (XV). Finally, the desired product is obtained by oxidation of (XV) with pyridine sulfur trioxide complex and Et3N in DMSO followed by diastereomer separation by HPLC.