Ethyl (diethoxyphosphoryl)methanesulfonate → Ethyl 2-[(3aR,4R,6R,6aR)-6-(6-chloro-9H-purin-9-yl)-2,2-dimethyltetrahydrofuro[3,4-d][1,3]dioxol-4-yl]ethenesulfonate

Participants

Reaction Conditions

Reaction Steps

To a solution of (diethoxy-phosphoryl)-methanesulfonic acid ethyl ester (7.991 g, 0.03070 mol) in THF (100 mL), at −78° C. under an atmosphere of nitrogen, was added dropwise 2.5M n-butyllithium in hexane (13 mL), and the solution was stirred for 30 minutes. Freshly prepared 6-(6-chloro-purin-9-yl)-2,2-dimethyl-tetrahydro-furo[3,4-d][1,3]-dioxole-4-carbaldehyde (13.10 g, 0.03026 mol) in THF (100 mL) was added over 15 min at −78° C. The reaction was allowed to slowly warm to −10° C. over 4 hours with stirring. The reaction was quenched with water (400 mL) and 5M ammonium chloride in water (100 mL) and extracted with methylene chloride (600 mL). The organic phase was concentrated in vacuo and the residue was purified by flash chromatography (30 to 100% EtOAc:hexanes) to yield the product as a foam (10.5 g, 81%).

Provenance & Evidence