Acetonitrile → tert-butyl (2S,3R,5E)-3-({[(1S)-2,2-dimethyl-1-({[(1R)-1-phenylethyl]amino}carbonyl)propyl]amino}carbonyl)-6-[3-methyl-(4-phenyl)phenyl]-2-(1-propyl)hex-5-enoate

Participants

Reaction Steps

According to the method of Preparation 3, tert-butyl (2S, 3R)-3-({[(1S)-2,2-dimethyl-1-({[(1R)-1-phenylethyl]amino}carbonyl)propyl]amino}carbonyl)-2-(1-propyl)hex-5-enoate (543 mg, 1.15 mmol) was reacted with 3-methyl-4-phenylbromobenzene (356 mg, 1.44 mmol) under palladium catalysis in a mixture of anhydrous acetonitrile and dimethylformamide (2:5, 7 mL) at 90° C. for 17 h. The mixture was concentrated under reduced pressure, poured into ethyl acetate (100 mL) and washed with water (2×100 mL), dried (MgSO4), and concentrated under reduced pressure. The residue was purified by flash chromatography (gradient elution with hexane:ethyl acetate) to give mainly tert-butyl (2S,3R,5E)-3-({[(1S)-2,2-dimethyl-1-({[(1R)-1-phenylethyl]amino}carbonyl)propyl]amino}carbonyl)-6-[3-methyl-(4-phenyl)phenyl]-2-(1-propyl)hex-5-enoate as a colourless gum (460 mg, 63%). 1H nmr suggested that two alkene isomers, the (5Z) and (4E) were also present. The mixture of alkenes was taken onto the next step (see c, below).

Provenance & Evidence