Hydrochloric Acid → HCID 67271813, compound

Participants

Reaction Steps

A mixture of protected tripeptide 7 (0.45 g, 0.80 mmol), conc. hydrochloric acid (38%, 0.13 cm3) and 10% palladium on activated carbon (0.08 g, 0.08 mmol) in 20% water/tetrahydrofuran (60 cm3) was stirred under an atmosphere of hydrogen at room temperature for 4 h. The solution was filtered through a Celite™ pad, washed with 20% water/tetrahydrofuran (2×30 cm3) and the filtrate evaporated to dryness to form GPyroE.HCl (0.19 g, 74%) as solid. GPyroE.HCl was shown to be exclusively the trans conformer by 1H and 13C NMR analysis5: mp 42-44° C.; [α]D −57.3 (c 0.09 in MeOH); OH (400 MHz; D2O) 2.07-2.14 (1H, m, Gluβ-HAHB), 2.20-2.25 (1H, m, Gluβ-HAHB), 2.30-2.34 (1H, m, Pyroβ-HAHB), 2.60-2.65 (3H, m, Pyro-HAHB and Gluγ-H2), 2.74-2.89 (2H, m, Pyroγ-H2), 4.48-4.59 (3H, Glyα-H2 and Gluα-H) and 4.93-4.95 (1H, m, Pyroα-H); δC (75 MHz, D2O) 22.5 (CH2, Pyroβ-C), 26.4 (CH2, Gluβ-C), 30.5 (CH2, Gluγ-C), 31.8 (CH2, Pyroγ-C), 44.3 (CH2, Glyα-C), 52.7 (CH, Gluα-C), 59.3 (CH, Pyroα-C), 168.5 (quat., Gly-CO), 173.6 (quat., Pyro-CO), 175.2 (quat., Pyro-CO), 177.6 (quat., Glu-CO) and 178.9 (quat., Glu-CO); m/z (FAB+) 316.1138 (MH+.C12H18N3O7 requires 316.1145).

Provenance & Evidence