1-[3(S)-[[N-(tert.butoxycarbonyl)-L-cysteinyl]amino]-2(R)-hydroxy-4-phenylbutyl]-N-tert.butyl-2(S)-piperidinecarboxamide → N-tert.butyl-1-[3(S)-[(L-cysteinyl)amino]-2(R)-hydroxy-4-phenylbutyl]-2(S)-piperidinecarboxamide

Participants

Reaction Steps

A solution of 930 mg of 1-[3(S)-[[N-(tert.butoxycarbonyl)-L-cysteinyl]amino]-2(R)-hydroxy-4-phenylbutyl]-N-tert.butyl-2(S)-piperidinecarboxamide in 7 ml of trifluoroacetic acid was stirred at 20° C. for 1 hour. The mixture was then evaporated to dryness and the residue was partitioned between dichloromethane and aqueous sodium bicarbonate solution. The organic phase was evaporated to give 650 mg of N-tert.butyl-1-[3(S)-[(L-cysteinyl)amino]-2(R)-hydroxy-4-phenylbutyl]-2(S)-piperidinecarboxamide as a colourless gum; MS: m/e [M+H]+.

Provenance & Evidence