合成路线1

The condensation of N-phthaloyl-L-phenylalanine (I) with 2(S)-amino-6-hydroxyhexanoic acid methyl ester (II) by means of HOBT and EDAC in DMF/dichloromethane gives the dipeptide (III), which is oxidized at the terminal OH with (COCl)2 in dichloromethane yielding the aldehyde (IV). The cyclization of (IV) with TFA in dichloromethane affords the tetrahydropyridine (V), which is cyclized again by means of trifluoromethanesulfonic acid in dichloromethane to provide the tricyclic carboxylic acid (VI). The esterification of (VI) with PhCH2Br and Cs2CO3 in DMF gives the benzyl ester (VII), which is treated with hydrazine to eliminate the phthalimido group and yielding intermediate (VIII). The reaction of the free amino group of (VIII) with 2(R)-benzyl-3-(benzyloxyamino)propionic acid (IX) by means of HOBT and EDAC in dichloromethane affords the amide (X), which is formylated with formic acid and acetic anhydride to provide the formamide (XI). Finally, this compound is debenzylated with H2 over Pd/C in methanol to furnish the target compound.