合成路线1

1) The mesylation of (2S,4R)-1-(tert-butoxycarbonyl)-4-hydroxypyrrolidine-2-carboxylic acid methyl ester (I) with mesyl chloride and triethylamine in dichloromethane gives the corresponding mesylate (II), which is treated with sodium benzoate in DMSO yielding the (2S,4S)-benzoate (III). The hydrolysis of (III) with K2CO3 in methanol affords (2S,4S)-1-(tert-butoxycarbonyl)-4-hydroxypyrrolidine-2-carboxylic acid methyl ester (IV), which is mesylated with mesyl chloride and triethylamine as before giving the mesylate (V). The reaction of (V) with sodium azide in DMSO yields the corresponding (2S,4R)-azide (VI), which is reduced with H2 over Pd/C in methanol affording (2S,4R)-4-amino-1-(tert-butoxycarbonyl)pyrrolidine-2-carboxylic acid methyl ester (VII). The acylation of (VII) with 4-chlorobenzenesulfonyl chloride (VIII) and triethylamine in dichloromethane gives the corresponding amide (IX), which is reduced with diisobutylaluminum hydride (DIBAL) in toluene/THF yielding the aldehyde (X). The Wittig condensation of aldehyde (X) with (4-carboxybutyl)triphenylphosphonium bromide (XI) by means of lithium bis(trimethylsilyl)amide (LBSA) in HMPT affords 6-[1-(tert-butoxycarbonyl)-4(R)-(4-chlorophenylsulfonamido)pyrrolidin-2(S)-yl]-5(Z)-hexenoic acid (XII), which is esterified and deprotected with methanol/HCl to give 6-[4(R)-(4-chlorophenylsulfonamido)pyrrolidin-2(S)-yl]-5(Z)-hexenoic acid methyl ester (XIII). The condensation of (XIII) with 3-(chloromethyl)pyridine (XIV) and triethylamine in refluxing THF yields 6-[4(R)-(4-chlorophenylsulfonamido)-1-(3-pyridylmethyl)pyrrolidin-2(S)-yl]-5(Z)-hexenoic acid methyl ester (XV), which is finally hydrolyzed with NaOH in methanol/water.