合成路线1

The reaction of (S)-2-amino-6-hydroxyhexanoic acid (I) with N-(ethoxycarbonyl)phthalimide (II) by means of Na2CO3 in water gives 6-hydroxy-2(S)-(phthalimido)hexanoic acid (III), which is esterified with benzyl bromide and Cs2CO3 in DMF yielding the benzyl ester (IV). The oxidation of the terminal OH group of (IV) with (COCl)2 in dichloromethane affords the aldehyde (V), which is methylated with AlMe3 in dichloromethane giving 6-hydroxy-2(S)-(phthalimido)heptanoic acid (VI). The oxidation of (VI) with oxalyl chloride as before yields the ketone (VII), which is methylated with TiCl4 and methylmagnesium chloride to provide the carbinol (VIII). The reaction of (VIII) with trimethylsilyl azide in dichloromethane gives the azido derivative (IX), which is cyclized by reduction with H2 over Pd/C in DMF yielding the perhydroazepinone (X). Elimination of phthalimido protecting group of (X) with hydrazine in methanol/dichloromethane affords 3(S)-amino-7,7-dimethylperhydroazepin-2-one (XI), which is protected with trityl chloride and TEA in dichloromethane to give the tritylamino compound (XII). The condensation of (XII) with ethyl 2-bromoacetate (XIII) by means of LHMDS, followed by deprotection with TFA affords the adduct (XIV) with a free amino group, which is acylated with 2(R)-benzyl-3-(benzyloxyamino)propionic acid (XV) by means of HOBT and EDAD in dichloromethane providing the amide (XVI). The formylation of (XVI) with formic acid and acetic anhydride gives the formamide (XVII), which is deprotected with H2 over Pd/C in ethanol yielding intermediate (XVIII). Finally, this compound is hydrolyzed with NaOH in methanol.