合成路线1

An alternative, stereoselective synthesis has been reported. The alkylation of the chiral N-acyl oxazolidinone (I) with benzyl L-2-[(trifluoromethylsulfonyl)oxy]propionate (II) leads to the succinic acid derivative (III). After hydrogenolysis of the benzyl ester group of (III), the resultant carboxylic acid (IV) is esterified with isobutylene and H2SO4 to afford the tert-butyl ester (V). Removal of the chiral auxiliary group of (V) is then effected by hydrolysis with lithium peroxide, yielding acid (VI). Subsequent coupling of (VI) with L-phenylglycine-N-methylamide (VII) provides diamide (VIII). Acidic tert-butyl ester cleavage in (VIII) gives acid (IX), which is condensed with O-benzyl hydroxylamine to furnish hydroxamate (X). The O-benzyl group of (X) is finally removed by catalytic hydrogenolysis over Pd/C.