Acetic Acid → 2',3'-Dideoxy-4'-thiocytosine

Participants

Reaction Conditions

Reaction Steps

The compound 13 (78 mg, 0.17 mmol) was dissolved in 4 mL tetrahydrofuran and then 1M tetrabutylammonium fluoride in THF (0.2 mL, 0.2 mmol) and acetic acid (11.5 μm, 0.2 mmol) were added, with subsequent stirring at 25° C. overnight. The reaction was diluted with 10 mL water and 10 mL ethyl ether followed by stirring for 5 minutes. The aqueous phase was washed with 20 mL ethyl ether and concentrated in vacuo to 1 mL. The aqueous residue was eluted through a 5-mL Dowex 1×4 (--OH) column with water to remove the tetrabutyl ammonium salts. The crude product (33 mg, 87%) was refractory to recrystallization and was precipitated as an amorphous solid with ethyl acetate and ethyl ether to afford 26.5 mg (69%) of 24; mp. 83°-85° C.; FAB MS 228 (M+ H)+ ; 1H NMR (DMSO-d6) δ 8.0 (d, 1, H-6), 7.1 (brd, 2, NH2), 6.15 (m, 1, 1'-H), 5.74 (d, 1, H-5), 5.1 (brs, 1, 5'-OH), 4.2 (q, EtOAc), 3.64 (m, 1, 5'-H), 3.5 (m, 2, 4'-H, 2.18 (m, 2.0 (m, 2, 2'-H, 3'-H), 1.99 (s, EtOAc), 1.82 3'-H), 1.18 (t, EtOAc).

Provenance & Evidence