N-[N2-[[3-oxo-2-[(1-oxoheptyl)amino]-1-methyl-3-(phenylmethoxy)-propoxy]carbonyl]-N6-[(phenylmethoxy)carbonyl]-(R)-6-[(phenylmethoxy)carbonyl]-L-lysyl]-D-Alanine Phenylmethyl Ester → N-[(R)-6-carboxy-N2-[[2-carboxy-1-methyl-2-[(1-oxoheptyl)amino]ethoxy]carbonyl]-L-lysyl]-D-Alanine

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Reaction Steps

A solution of 1a-1 (140 mg, 0.15 mmol) in EtOAc/EtOH (5 mL:15 mL) is hydrogenated over Pd(OH)2 (Pearlman's catalyst, 20% on C, 100 mg) using a Parr apparatus at an initial pressure of 70 psi. After 5.5 h, filtration and evaporation gives a colorless glass. The latter is triturated with ether and the sides of the flask are scraped to provide a white crystalline powder. The ether solution is removed with a syringe and the solid is washed with two more portions of ether, dried, and characterized as 1a-11: NMR (CD3OD) δ 0.89 (m, 3 H), 1.22 (d, J=6.5, 3 H), 1.24-1.39 (m, 6 H), 1.42 (d, J=7.3, 3 H), 1.45-1.99 (m, 8 H), 2.26 (t, J≈7.5, 2H), 3.62 (m, 1 H), 4.06 (m, 1 H), 4.41 (m, 1 H), 4.89 (br s for OH, NH; one hidden CH signal), 5.14 (m, 1 H); MS (HR-FAB) m/z 519.2671 (M+H calcd. for C22H39N4O10, 519.2666).

Provenance & Evidence