合成路线1

3) The alkylation of 5(S)-(tert-butyldimethylsilyloxymethyl)tetrahydrofuran-2-one (XII) by means of benzyl bromide (XIII) and lithium diisopropylamide (LDA) gives the corresponding 3(R)-benzyl derivative (XIV), which is deprotected with aqueous HF, yielding the hydroxymethyl compound (XV). The esterification of (XV) with trifluoromethanesulfonic anhydride affords the corresponding triflate (XVI), which is condensed with the chiral piperazine (VII) by means of diisopropylethylamine in isopropanol, giving the substituted furanone (XVII). Ring opening of the furanone (XVII) with LiOH, DME and imidazole yields the substituted hydroxypentanamide (XVIII), which is protected with tert-butyldimethylsilyl chloride to afford the protected amide (XIX). The trans-amidation of (XIX) with 2-hydroxyindan-1-amine (II) by means of 1-ethyl-3-[3-(dimethylamino)propyl]carbodiimide (EDC) and 1-hydroxybenzotriazole (HOBt) in DMF gives the protected dihydroxy diamide (XX), which is deprotected with trimethylsilyl triflate, affording the dihydroxy diamide (VII), already obtained. This compound is then alkylated with 3-(chloromethyl)pyridine (IX) as before.