合成路线1

8. The enantioselective monoacetylation of isosorbide (I) by means of vinyl acetate (VI) catalyzed by Pig liver esterase in dichloromethane gives isosorbide 2-O-acetate (VII), which is nitrated with HNO3 in acetic anhydride to yield isosorbide 2-O-acetate-5-O-nitrate (VIII). Finally, this compound is deacetylated by means of K2CO3 in methanol. 9. The enantioselective monoacylation of isosorbide (I) by means of vinyl butyrate (IX) catalyzed by Chiraclec-BL in THF or Carlsberg subtilisin in tert-butanol gives isosorbide 2-O-butyrate (X), which is nitrated with HNO3 in acetic anhydride to yield isosorbide 2-O-butyrate-5-O-nitrate (XI). Finally, this compound is deacylated by means of K2CO3 in methanol. 10. The acylation of isosorbide (I) with acetic anhydride and pyridine gives the diacetate (XII), which is enantioselectively monodeacetylated by means of lipase from Pseudomonas fluorescens in THF to yield isosorbide 2-O-acetate (VII). This compound is then nitrated to (VIII) and finally deacetylated as already described. 11. The acylation of isosorbide (I) with HOAc and Ac2O gives (after purification by crystallization) isosorbide 2-O-acetate (VII), which is nitrated to (VIII) and finally deacetylated as already described. 12. The acylation of isosorbide (I) with isobutyric acid (XIII) by means of sulfuric acid in refluxing chlorobenzene/toluene gives isosorbide 2-O-isobutyrate (XIV), which is nitrated with HNO3/H2SO4 to yield isosorbide 2-O-isobutyrate-5-O-nitrate (XV). Finally, this compound is deacylated by means of NaOH in toluene/water. 13. The nitration of isosorbide (I) by means of HNO3 in HOAc/Ac2O gives a 3.5/1 mixture of isosorbide-5-O-nitrate and isosorbide 2-O-nitrate that is separated by column chromatography over alumina. 14. The nitration of isosorbide (I) with HNO3 in benzene/HOAc/Ac2O, followed by a purification step yields the target isosorbide-5-O-nitrate.