A novel method for synthesizing isonucleosides, a new class of anti-HIV nucleosides, is described. 2,2- Dimethyl- 1,3- dioxan- 5- one was converted into a dioxabicyclohexane derivative in six steps. After cleaving the epoxide group with thiophenol, the resulting product was subjected to the Mitsunobu reaction in the presence of a nucleobase to give the desired isonucleoside derivative via migration of the thiophenyl group. Removal of the thiophenyl group under radical conditions followed by deprotection led to the 4'- substituted 2', 3'- dideoxyisonucleosides as a racemic mixture.
A novel method for synthesizing isonucleosides, a new class of anti-HIV nucleosides, is described. 2,2- Dimethyl- 1,3- dioxan- 5- one was converted into a dioxabicyclohexane derivative in six steps. After cleaving the epoxide group with thiophenol, the resulting product was subjected to the Mitsunobu reaction in the presence of a nucleobase to give the desired isonucleoside derivative via migration of the thiophenyl group. Removal of the thiophenyl group under radical conditions followed by deprotection led to the 4'- substituted 2', 3'- dideoxyisonucleosides as a racemic mixture.
Design and Synthesis of Isonucleosides Constructed on a 2-Oxa-6-thiabicyclo[3.2.0]heptane Scaffold
other hand, was converted into the corresponding dimesylate, which was then treated with mercury acetate and trifluoroaceticacid to remove the PMB group. The resulting thiol derivative was treated with DBU to give the desired isonucleoside constructed on a 2-oxa-6-thiobicyclo[3.2.0]heptane scaffold after deprotection. The optimized conformer of the isonucleoside was calculated using DFT at the B3LYP/6-31G**