反应详情

Another preferred embodiment of the present invention is exemplified in FIG. 4, and comprises reacting cytosine, BSA and SnCl4/acetonitrile with 1,2,3,5-tetra-O-benzoyl-2-C-methyl-β-D-ribofuranose (4) from the first embodiment of the invention to provide 4-amino-1-(3,4-dibenzoyloxy-5-benzoyloxymethyl-3-methyl-tetrahydrofuran-2-yl)-1H-pyrimidin-2-one (5); and reacting (5) with NaOMe/MeOH to provide (4-amino-1-(3,4-dihydroxy-5-hydroxymethyl-3-C-methyl-tetrahydrofuran-2-yl)-1H-pyrimidin-2-one) (6), also known as β-D-2′-C-methyl-cytidine. The use of cytosine as a starting material rather than benzoyl-cytosine improves the “atom economy” of the process and simplifies purification at later steps.