Boron Trichloride → (2R,3R,4R,5R)-2-(4-Chloro-7H-pyrrolo[2,3-d]pyrimidin-7-yl)-3-ethynyl-5-(hydroxymethyl)tetrahydrofuran-3,4-diol

Participants

Reaction Conditions

Reaction Steps

To a cold (−78° C.) solution of (2R,3R,4R,5R)-2-(4-Chloro-pyrrolo[2,3-d]pyrimidin-7-yl)-4-(2,4-dichlorobenzyloxy)-5-(2,4-dichlorobenzyloxymethyl)-3-ethynyl-tetrahydrofuran-3-ol I-5 (150 mg, 0.24 mmol, 1 equiv.) in dry DCM (20 ml) is added 1M solution of BCl3 in DCM (2.4 ml, 2.4 mmol, 10 equiv.) drop-wise and stirred at −78° C. for about 5 h. The reaction mixture is quenched with MeOH (15 mL) at 0° C. and stirred for 30 min. Solvent is evaporated and dried together with silica gel (4 ml), the crude product on silica gel is purified by flash chromatography (DCM:methanol=90:10) to give (2R,3R,4R,5R)-2-(4-Chloro-pyrrolo[2,3-d]pyrimidin-7-yl)-3-ethynyl-5-hydroxymethyl-tetrahydrofuran-3,4-diol I-6 as a brown foam.

Provenance & Evidence