2,3,5-tri-O-benzoyl-2-C-methyl-D-ribofuranose

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of the compound from Step C (0.075 g, 0.44 mmol), 2,3,5-tri-O-benzoyl-2-C-methyl-D-ribofuranose [Harry-O'kuru, Rogers E.; Smith, Jennifer M.; Wolfe, Michael S, “A Short, Flexible Route toward 2′-C-Branched Ribonucleosides,” J. Org. Chem., 62: 1754-1759 (1997)] (4-5) (0.25 g, 0.53 mmol) and triphenylphosphine (0.23 g, 0.88 mmol) in THF (15 mL) was added diethyl azodicarboxylate (DEAD) (0.14 mL, 0.88 mmol). The reaction mixture was stirred at room temperature overnight. The solution was directly adsorbed onto silica gel and purified over silica gel using ethyl acetate/hexane 1:9 as the eluent Appropriate fractions were dissolved in dioxane (3 mL) and liquid ammonia (4 mL) and the mixture was heated in a steel bomb at 85° C. for 24 h. The solvent was evaporated and the residue was purified over silica gel using methanol/dichloromethane (1:9) as the eluent. Fractions containing the desired compound were pooled and evaporated in vacuo to give the title compound. purified over silica gel were dissolved in dioxane (3 mL) liquid ammonia (4 mL) and the mixture was heated in a steel bomb at 85° C. for 24 h The solvent was evaporated the residue was purified over silica gel Fractions containing the desired compound evaporated in vacuo

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of the compound from Step C (0.075 g, 0.44 mmol), 2,3,5-tri-O-benzoyl-2-C-methyl-D-ribofuranose [Harry-O'kuru, Rogers E.; Smith, Jennifer M.; Wolfe, Michael S, “A Short, Flexible Route toward 2′-C-Branched Ribonucleosides,” J. Org. Chem., 62: 1754-1759 (1997)] (4-5) (0.25 g, 0.53 mmol) and triphenylphosphine (0.23 g, 0.88 mmol) in THF (15 mL) was added diethyl azodicarboxylate (DEAD) (0.14 mL, 0.88 mmol). The reaction mixture was stirred at room temperature overnight. The solution was directly adsorbed onto silica gel and purified over silica gel using ethyl acetate/hexane 1:9 as the eluent Appropriate fractions were dissolved in dioxane (3 mL) and liquid ammonia (4 mL) and the mixture was heated in a steel bomb at 85° C. for 24 h. The solvent was evaporated and the residue was purified over silica gel using methanol/dichloromethane (1:9) as the eluent. Fractions containing the desired compound were pooled and evaporated in vacuo to give the title compound. purified over silica gel were dissolved in dioxane (3 mL) liquid ammonia (4 mL) and the mixture was heated in a steel bomb at 85° C. for 24 h The solvent was evaporated the residue was purified over silica gel Fractions containing the desired compound evaporated in vacuo

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of the compound from Step C (0.075 g, 0.44 mmol), 2,3,5-tri-O-benzoyl-2-C-methyl-D-ribofuranose [Harry-O'kuru, Rogers E.; Smith, Jennifer M.; Wolfe, Michael S, “A Short, Flexible Route toward 2′-C-Branched Ribonucleosides,” J. Org. Chem., 62: 1754-1759 (1997)] (4-5) (0.25 g, 0.53 mmol) and triphenylphosphine (0.23 g, 0.88 mmol) in THF (15 mL) was added diethyl azodicarboxylate (DEAD) (0.14 mL, 0.88 mmol). The reaction mixture was stirred at room temperature overnight. The solution was directly adsorbed onto silica gel and purified over silica gel using ethyl acetate/hexane 1:9 as the eluent Appropriate fractions were dissolved in dioxane (3 mL) and liquid ammonia (4 mL) and the mixture was heated in a steel bomb at 85° C. for 24 h. The solvent was evaporated and the residue was purified over silica gel using methanol/dichloromethane (1:9) as the eluent. Fractions containing the desired compound were pooled and evaporated in vacuo to give the title compound. purified over silica gel were dissolved in dioxane (3 mL) liquid ammonia (4 mL) and the mixture was heated in a steel bomb at 85° C. for 24 h The solvent was evaporated the residue was purified over silica gel Fractions containing the desired compound evaporated in vacuo

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: The protective group at C-1 of the ribofuranose is made in the immediately preceding step. Benzoyl chloride is added to a 5° C. solution of 2,3,5-tri-O-benzoyl-2-C-methyl-D-ribofuranose in approximately a 2:1 molar ratio, along with DMAP and TEA in anhydrous DME. The reaction is stirred and allowed to run overnight, after which it is quenched with ice water and aqueous sodium carbonate solution. THF is then removed, and the mixture is extracted with ethyl acetate. Washing, drying and solvent removal produces a thick, oily product. The latter has added to it tert-butyl methyl ether, heptane and water, and is stirred for approximately 2 hours at about 20° C. The final product, 1,2,3,5-tetra-O-benzoyl-2-C-methyl-β-D-ribofuranose, is obtained in 52% yield and greater than 98% purity, after washing and vacuum drying (see FIG. 1, compound 4, Scheme 1). after which it is quenched with ice water and aqueous sodium carbonate solution THF is then removed the mixture is extracted with ethyl acetate Washing drying solvent removal produces a thick, oily product is stirred for approximately 2 hours at about 20° C