A novel method for the design and synthesis of an isonucleoside containing a 2-oxa-6- thiobicyclo [3.2. 0] heptane skeleton is described. 2, 2-Dimethyl-1, 3-dioxan-5-one 13 was converted into a dioxabicyclohexane derivative in six steps. After cleavage of the epoxide group with a thiol (thiophenol or PMB mercaptan), the resulting product was subjected to the Mitsunobu reaction in the presence of a nucleobase. The reaction proceeded via the ...
