An acyclonucleoside synthesis was investigated on the regioselective introduction of an acyclochain. We found that iodotrimethylsilane catalyzed the reaction of acyclochain introduction as well as its migration from S-2 to N-1 of 2-thiothymine and from N-7 to N-9 position of guanine. By taking the findings into account, several acyclonucleosides were synthesized in a simple one-pot procedure.