Benzyl Nalpha-(Nalpha,Nepsilon-bis(t-butoxycarbonyl)-L-lysinoyl)-Nepsilon-(t-butoxycarbonyl)-L-lysine → (2S)-2-[[(2S)-2,6-Bis(tert-butoxycarbonylamino)hexanoyl]amino]-6-(tert-butoxycarbonylamino)hexanoic acid

Participants

Reaction Steps

A slurry of Pd—C (10% wt, 117 mg) in dry MeOH (2 mL) was added to a solution of benzyl ester 50 (1.17 g, 1.76 mmol) in dry MeOH (8.8 mL). The reaction vessel was flushed with hydrogen gas and stirred with a hydrogen balloon for 2 h 25 min. The reaction mixture was then filtered over celite to remove the catalyst. After rinsing the catalyst with small portions of MeOH, the combined filtrates were concentrated to dryness, providing acid 51 as a white solid (969 mg, 96%). 1H NMR (400 MHz, DMSO-d6) δ 1.20-1.48 (m, 36H), 1.52-1.60 (m, 2H), 1.63-1.72 (m, 1H), 2.84-2.89 (m, 4H), 3.85-3.91 (m, 1H), 4.09-4.15 (m, 1H), 6.75 (bs, 2H), 6.80 (d, J=8.1 Hz, 1H), 7.88 (d, J=7.8 Hz, 1H).

Provenance & Evidence