Acetic Acid → {4-[(2S,4R)-1-Boc-4-(t-butyldimetylsilyl)oxypyrrolidin-2-ylmethyl]amino-2-phenylbenzoyl}methionine methyl ester

Participants

Reaction Steps

To a solution of 0.75 g (2.09 mmol) of [2-phenyl-4-aminobenzoyl]methionine methyl ester (compound 8) and 0.7 g (2.1 mmol) of (2S,4R)-1-Boc-4-[t-butyldimethylsilyloxy]-pyrrolidin-2-aldehyde, prepared as in Example 171B, in 10 ml of methanol were added 1 ml of acetic acid, followed by 0.2 g (3.1 mmol) of sodium cyanoborohydride. The reaction mixture was stirred overnight. After removal of the solvent, the residue was partitioned with ethyl acetate and 5% sodium bicarbonate, and extracted 3 times with ethyl acetate. The combined organic solution was washed with water and brine, dried over magnesium sulfate, and solvent was removed. The residue was flash-chromatographed on silica gel (2:1 hexanes-ethyl acetate) to yield 261 mg (74%) of {4-[(2S,4R)-1-Boc-4-(t-butyldimetylsilyl)oxypyrrolidin-2-ylmethyl]amino-2-phenylbenzoyl}methionine methyl ester as a white solid: mp 48° C.; [α]25D−15.6 (c=1.03, CHCl3);

Provenance & Evidence