Boron trifluoride etherate → (2-Chloro-5-((3S,4R,5R,6R)-3,4,5-tris(benzyloxy)-6-(benzyloxymethyl)-tetrahydro-2H-pyran-2-yl)benzyloxy)triisopropylsilane

Participants

Reaction Conditions

Reaction Steps

To a stirred −50° C. solution of (3R,4S,5R,6R)-3,4,5-tris(benzyloxy)-6-(benzyloxymethyl)-2-(4-chloro-3-((triisopropylsilyloxy)methyl)phenyl)tetra-hydro-2H-pyran-2-ol (198 mmol) from Step 4 in dichloromethane (500 mL) was added triethylsilane (63 mL, 396 mmol) followed by boron trifluoride diethyl etherate (50 mL, 396 mmol) at a rate such that the reaction temperature was maintained between −40 and −50° C. The solution was allowed to warm to −10° C. over 2 h prior to quenching with saturated potassium carbonate solution. After removal of organic volatiles under reduced pressure, the residue was partitioned between ethyl acetate and water. Following extraction of the aqueous layer with ethyl acetate, the combined organic layers were washed with water prior to drying over magnesium sulfate. Filtration and concentration under reduced pressure yielded the title compound as a yellow oil which was used without further purification.

Provenance & Evidence