Zhou, X.-T.; Rehman, A.; Li, C.; Savage, P. B. Org. Lett. 2000, 2, 3015-3018. Preparation of a protected triamino-analogue of cholic acid and sequential incorporation of amino acids in solution and on a solid support.
We have prepared a triamine derivative of cholic acid with protecting groups on the amines that allow sequential amide formation. The triamine was formed from 3 alpha,7 alpha, 12 alpha-trihydroxycholan-24-ol with good stereoselectivity. Sequential removal of the amine protecting groups and amide formation was achieved in high-yielding steps and was performed in solution and on a solid support.