Carbamate → 2,2-Dimethoxypropane

Participants

Reaction Steps

Preparation of compounds 6 and 7 starting from compound 3 is shown in the synthesis scheme below. Compound 3 was prepared from 6-chloropurineriboside 1 and 3 (R)-aminotetrahydrofuran following the procedure reported earlier (U.S. Pat. No. 5,789,416). Protection of the 2′ and 3′ hydroxy groups as an acetonide with 2,2-dimethoxypropane in the presence of TsOH(cat.) gave 4. Reaction of 4 with CDI in THF followed by treatment with 40% aq.methylamine gave carbamate 5. Deprotection of the 2′,3′ acetonide with 80% AcOH/water at 80-90 C. gave carbamate 6. Esterification of 6 with acetic anhydride in pyridine gave diester 7.

Provenance & Evidence