Tetrabutylammonium Fluoride → 2-(R)-(3-(R)-(hydroxymethyl)4-(S)-phenylpyrrolidin-1-yl)-3-(cyclobutyl)propionic acid, benzyl ester

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Reaction Steps

A solution of 3.20 g (6.3 mmol) of 2-(R)-(3-(R)-(t-butyldimethylsilyloxymethyl)-4-(S)-phenylpyrrolidin-1-yl)-3-(cyclobutyl) propionic acid, benzyl ester (from Step A) in 40 mL of THF at 0° C. was treated with 10 mL of 1.0 M tetrabutylammonium fluoride solution in THF. The resulting mixture was warmed to rt and stirred for 2.5 h. The reaction mixture was partitioned between 200 mL of ether and 100 mL of 50% sat'd NaHCO3 and the layers were separated. The organic layer was dried over MgSO4 and concentrated. Flash chromatography on 100 g of silica gel using 2:1 v/v hexanes/ether as the eluant afforded 2.34 g (94%) of the title compound: 1H NMR (500 MHz) δ1.56-2.07 (8H), 2.15 (br s, 1H), 2.27-2.37 (2H), 2.64 (t, J=11.0, 1H), 2.80 (dd, J=6.5, 11.0), 3.04-3.11 (2H), 3.23-3.30 (2H), 3.56 (dd, J=7.5, 13.0, 1H), 3.68 (dd, J=5.5, 13.0, 1H), 5.15 (ABq, J=20.0, 2H), 7.17-7.40 (10H).

Provenance & Evidence