All of the three stereoisomers of 5-deoxy-5-[4-(3-phenylthiopropyl)piperazin-1-yl]-1,4:3,6-dianhydro-L-iditol 2-nitrate (KF-14124; 4) were synthesized from a common key intermediate (8). Among modern cardiovascular therapeutic agents, organic nitrates such as nitroglycerin (GTN) and isosorbide dinitrate (1; ISDN) still remain the basis of therapy. In the group of 1,4:3,6-dianhydrohexitol dinitrates such as ISDN (1) (exo,endo), there are two other stereoisomers, which are isomannide dinitrate [2; IMDN (endo,endo)] and isoidide dinitrate [3; IIDN (exo,exo)]. The literature indicates that IIDN is the most active among them. Recently, we have shown that a 1,4:3,6-dianhydrohexitol nitrate derivative, KF-14124 (4), which has an (exo,exo) configuration, exhibited potent vasodilatory activity [minimum effective dose (MED) in the angina pectoris model (Table 1); MED in propranolol-induced heart failure model (LVEDP; left ventricular end diastolic pressure in dog): 0.1 mg/kg id for KF-14124 and >0.3 mg/kg for ISDN (1)]. However, it is still unclear whether an (exo,exo) isomer is the most potent vasodilator among the mononitrate derivatives. Thus, we synthesized the other three stereoisomers of 4. In conclusion, we have succeeded in obtaining all of the three stereoisomers of KF-14124 (4) from a common key intermediate 8, using the Mitsunobu reaction, an intramolecular S_N2 reaction, and a stepwise method for the preparation of a piperazine ring, respectively. However, as can be seen from Table 1, all of these isomers exhibited less potent activity than 4 (KF-14124) which is now under preclinical studies as a new orally absorbable nitrate.