Electrophilic Substitution at C(7) of a Protected 7-Deaza-2’-deoxyguanosine – The 2’-Deoxyribonucleoside Parent Analogue of Queuosine #

In this manuscript we report on the regioselective electrophilic substitution at C(7) of 7-[2-deoxy-3,5-bis-O-(2-methylpropanoyl)-ß-D-erythro-pentofuranosyl]-2-(formylamino)-4-methoxy-7H-pyrrolo[2,3-d]pyrimidine (2) – a protected precursor of 7-deaza-2’-deoxyguanosine - using N,N-dimethyl-methyleniminium iodide (Eschenmoser’s salt) yielding the Mannich compound 4