Triethylamine → (R)-alpha-[(3-Benzyloxycarbonylamino-3-methyl-1-oxobutyl)amino]benzenebutanoic acid allyl ester

Participants

Reaction Steps

D-Homophenylalanine allyl ester (350 mg; 1.60 mmol), triethylamine (445 μl; 3.19 mmol) and 3-t-butoxycarbonylamino-3-methylbutanoic acid (412.8 mg; 1.64 mmol) were dissolved in dry methylene chloride (3 ml) and stirred at room temperature to give a homogeneous solution. BOP was added to the solution over 5 minutes and the reaction mixture stirred together at room temperature for 12 h. The reaction mixture was quenched by adding brine (10 ml) directly to the reaction. The crude products were isolated by extraction with methylene chloride (2×25 ml); the combined methylene chloride extracts dried with powdered anhydrous magnesium sulfate, filtered and evaporated under reduced pressure. The pale yellow oil thus obtained was subjected to column chromatography on silica gel using an eluant of ethyl acetate and hexanes (1:1 v/v). In this way, 432 mg (59.7%) of the desired product was isolated as a colorless oil. FAB-MS: -calculated for C26H32N2O5 452.2; found 453.4 (M+1).

Provenance & Evidence