Acetic Acid → HCID 54428006, compound

Participants

Reaction Steps

A solution of the protected tripeptide of Example 2 (11.2 g., 0.018 mole) in methanol (250 ml.) containing 5% Pd on BaSO4 (6.75 g.) and 1 ml. of glacial acetic acid was hydrogenated as described above for the preparation of the product of Example 2 and evaporated to dryness. The resultant oil was taken up in DMF (70 ml.), cooled to 0° and coupled with N-benzyloxycarbonyl-O-t-butyl-L-threonine N-hydroxysuccinimide ester (7.32 g., 0.018 mole). Workup as described for Example 1 was followed by chromatography on Sephadex LH 20 using 95% ethanol as eluant. Crystallization from ether-gexane gave 12.9 g. (9.8%) of white amorphous product; m.p. 113.5°-115°; [α]D25 + 23.63° (C, 1 DMF); Rf 0.75 (B). Anal. calcd for C41H62N4O10 : C, 63.87; H, 8.11; N, 7.27. Found: C, 63.99; H, 8.18; N, 7.21.

Provenance & Evidence