p-Toluenesulfonic acid → (5R,6R,6aR)-5-((tert-butyldiphenylsilyloxy)methyl)-2,2,6a-trimethyl-tetrahydrofuro[3,2-d][1,3]dioxol-6-yl 4-methylbenzenesulfonate

Participants

Reaction Steps

To a mixture of compounds (2R,3R,4R)-2-((tert-butyldiphenylsilyloxy)methyl)-4,5-dihydroxy-4-methyl-tetrahydrofuran-3-yl 4-methylbenzenesulfonate (from step 3) (58 g, 0.104 mol), 2,2-dimethoxy propane (25.7 mL, 0.209 mol) in 500 mL of anhydrous CH2Cl2 at 0° C., PTSA was added and stirred at room temperature for 2 h. The reaction mixture was poured into saturated NaHCO3 solution and organic layers were washed with brine, dried over anhydrous Na2SO4, filtered and concentrated. Purified by column chromatography using hexane and ethyl acetate as a gradient mixture to give 57.2 g of the title compound (92% yield).

Provenance & Evidence