4-Methoxybenzyl 2,2,2-Trichloroacetimidate → HCID 57887023, compound

Participants

Reaction Steps

Boron trifluoride etherate (5.0 μL, 39 μmol) was added to a stirred solution of 1,1-dimethylethyl 2-(2-{[(1,1-dimethylethyl)(dimethyl)silyl]oxy}ethyl)-3-hydroxy-5-(4-iodophenyl)pentanoate (5.14 g, 9.63 mmol) and 4-methoxybenzyl 2,2,2-trichloroethanimidoate (4.05 g, 14.4 mmol) in tetrahydrofuran (40 mL) at 0° C. under nitrogen. The reaction was allowed to warm to room temperature at which stirring was continued for 2 h. A further portion of boron trifluoride etherate (5.0 μL, 39 μmol) was then added and stirring was continued at room temperature for a further 2 h. Two further additions of boron trifluoride etherate (5.0 μL, 39 μmol) followed by stirring at room temperature for 2 h were carried out before evaporation of the solvent. The residue was chromatographed on silica gel (0% to 10% diethyl ether: cyclohexane) to give the title compound (4.14 g, 66%) as a yellow oil which was a mixture of diastereomers. LC/MS: 4.78 min; z/e 655, calcd (M+1) 655. 1H NMR (400 MHz: CDCl3): 7.55 (2H), 7.25 (2H), 6.90 (2H), 6.80 (2H), 4.55 (1H), 4.35 (1H), 3.80 (3H), 3.65 (1H), 3.55 (1H), 2.95 (1H major), 2.80 (1H minor), 2.70 (1H), 2.55 (1H), 1.95-1.60 (4H), 1.45 (9H), 0.85 (9H), 0.5 (6H).

Provenance & Evidence