TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Component: The reducing agent comprises potassium borohydride, sodium borohydride, borohydride, boron hydrogenation zinc, calcium borohydride, sodium cyanoborohydride, sodium triacetoxyborohydride, triethyl boron lithium, tri-sec-butyl boron lithium, lithium aluminum or tri butoxy lithium aluminum hydride, preferably potassium borohydride, sodium borohydride, or lithium borohydride. The diluted acid comprises diluted hydrochloric, acetic, diluted sulfuric acid or diluted nitric acid, preferably dilute hydrochloric acid. The alkali comprises sodium hydroxide, potassium hydroxide, lithium hydroxide, strontium hydroxide, potassium carbonate, potassium bicarbonate, sodium carbonate, sodium bicarbonate or ammonia (preferred). The alcohol is methanol (preferred), ethanol or isopropanol. The reducing agent comprises potassium borohydride, sodium borohydride, borohydride, boron hydrogenation zinc, calcium borohydride, sodium cyanoborohydride, sodium triacetoxyborohydride, triethyl boron lithium, tri-sec-butyl boron lithium, lithium aluminum or tri butoxy lithium aluminum hydride, preferably potassium borohydride, sodium borohydride or lithium borohydride.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Method: The acylation reaction is carried out in solvent and in the presence of catalyst at - 60 to - 5 (preferably - 25 to - 20) degrees C. The acyl-silanization cytosine (IV) is prepared by mixing acyl cytosine, catalyst, silanization reagent and solvent. The reduction step is carried out in the presence of a reducing agent. The hydrolysis is carried out in the presence of diluted acid. The step of removing acyl is carried out in alkali condition or alcohol solution. Preferred Component: The acylating agent comprises acetic anhydride, acetyl chloride, bromide, acetyl iodide, acetate, acetic, propionic, propionyl chloride, propylene acyl bromide, acrylic acid iodine, propionate or propionic acid, preferably acetic anhydride or propionic anhydride. The solvent is tetrahydrofuran (preferred), trichloromethane, methylene dichloride or their mixture. The catalyst is 4 pyridine (DMAP) (preferred), N, N-dicyclohexyl carbodiimide (DCC) or their mixtures. The acyl cytosine comprises N-formyl cytosine, N-acetyl cytosine (preferred), N-hydroxy cytosine, N-isopropyl acyl cytosine, N-butyryl-cytosine; the catalyst comprises ammonium sulfate (preferred), ammonium chloride, methanesulfonic, toluenesulfonic acid; the silylation agent comprises trimethyl chlorosilane, iodotrimethylsilane, hexamethyl disilazane (preferred); and the solvent comprises dichloromethane, trichloromethane (preferred), benzene, toluene. The Lewis acid comprises iodotrimethylsilane (preferred), trimethyl chlorosilane, trimethyl chlorosilane or potassium iodide or sodium iodide mixture. Preferred Definitions:    R=formyl, acetyl, propionyl, isopropyl, butyryl, isobutyryl, valeryl, phenylacetyl, styrene-acrylic acid, benzoyl, p-benzoyl, methane sulfonyl, ethane sulfonyl, benzenesulfonyl, toluene sulfonyl, benzenesulfonyl or acetaminophen;    X=acetyl or propionyl; and    Y'=phenyl or methyl phenyl.