Trifluoroacetic acid → (S)-1-((S)-1-(6-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)hexanoyl)pyrrolidine-2-carbonyl)pyrrolidine-2-carboxylic acid

Participants

Reaction Steps

To a mixture of the tert-butyl ester 77 in dichloromethane (4 mL) was added trifluoroacetic acid (4 mL). After 40 min the reaction was determined to be complete by HPLC analysis. The mixture was concentrated under reduced pressure and the resulting residue was dissolved in dichloromethane and concentrated a second time to give 37 mg (100%) of 78 as a white solid: 1H-NMR (400 MHz, CDCl3) δ 6.68 (s, 2H), 4.62 (m, 2H), 3.81 (m, 1H), 3.70 (m, 1H), 3.57 (m, 2H), 3.45 (m, 2H), 2.40-1.91 (m, 10H), 1.70-1.45 (m, 4H), 1.33 (m, 2H); MS (ES+) m/z 406.2 [M+H]+.

Provenance & Evidence